Question: What battle had the code name Operation Iceberg, Battle of Okinawa or Second Battle of Bull Run?

full_context: Document 1: Battle of Cedar Mountain: The Battle of Cedar Mountain, also known as Slaughter's Mountain or Cedar Run, took place on August 9, 1862, in Culpeper County, Virginia, as part of the American Civil War. Union forces under Maj. Gen. Nathaniel P. Banks attacked Confederate forces under Maj. Gen. Thomas J. "Stonewall" Jackson near Cedar Mountain as the Confederates marched on Culpeper Court House to forestall a Union advance into central Virginia. After nearly being driven from the field in the early part of the battle, a Confederate counterattack broke the Union lines resulting in a Confederate victory. The battle was the first combat of the Northern Virginia Campaign.
Document 2: Operation Downfall: Operation Downfall was the proposed Allied plan for the invasion of Japan near the end of World War II. The planned operation was abandoned when Japan surrendered following the atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war and the Soviet invasion of Manchuria. The operation had two parts: Operations Olympic and Coronet. Set to begin in November 1945, Operation Olympic was intended to capture the southern third of the southernmost main Japanese island, Kyūshū, with the recently captured island of Okinawa to be used as a staging area. Later, in the spring of 1946, Operation Coronet was the planned invasion of the Kantō Plain, near Tokyo, on the Japanese island of Honshu. Airbases on Kyūshū captured in Operation Olympic would allow land-based air support for Operation Coronet. If Downfall had taken place, it would have been the largest amphibious operation in history.
Document 3: Iwo Jima: Iwo To (硫黄島 , Iō-tō , "sulfur island") , known in English as Iwo Jima (    ), is an island of the Japanese Volcano Islands chain south of the Ogasawara Islands and together with them forms the Ogasawara Archipelago also known as the Bonin Islands. The island of 21 km (8 square miles) is 1200 km south of mainland Tokyo and is administered as part of Ogasawara, one of the eight villages of Tokyo inhabited only by Japan Self-Defense Forces and used by the U.S. Navy for carrier practice. It was the setting of the February–March 1945 Battle of Iwo Jima involving the United States and a small number of elements of the British Pacific Fleet versus the Empire of Japan during World War II. The island grew in recognition outside Japan when the photograph "Raising the Flag on Iwo Jima" was taken on Mount Suribachi, the highest point at 160 metres (528 feet), during the battle by Associated Press photographer Joe Rosenthal. The U.S. occupied Iwo Jima until 1968 when it was returned to Japan.
Document 4: Northern Virginia Campaign: The Northern Virginia Campaign, also known as the Second Bull Run Campaign or Second Manassas Campaign, was a series of battles fought in Virginia during August and September 1862 in the Eastern Theater of the American Civil War. Confederate General Robert E. Lee followed up his successes of the Seven Days Battles in the Peninsula Campaign by moving north toward Washington, D.C., and defeating Maj. Gen. John Pope and his Army of Virginia.
Document 5: Operation Flintlock (World War II): Operation Flintlock was the campaign against the Japanese in the Marshall Islands in the Pacific theatre of World War II, from 31 January to 4 February 1944. The operation involved the invasions of Kwajalein, Eniwetok, and Majuro atolls. Admiral Nimitz, Commander of the U. S. Pacific Fleet, chose two islands in Kwajalein Atoll, Roi-Namur Island and Kwajalein Island, as primary targets in the U. S. invasion of the Marshall Islands.  Kwajalein Atoll contained communication and weather observation units and two Japanese airstrips on Roi-Namur and Kwajalein Islands, a seaplane base situated at Ebeye Island, a submarine base at Roi-Namur Island, and other Japanese installations scattered on various islands throughout Kwajalein atoll.  Kwajalein atoll, particularly Roi-Namur and Kwajalein Islands, were subjected to heavy bombardment. This attack also sank a large number of Japanese ships in Kwajalein Lagoon. Bitter fighting between Japanese forces and the U. S. 4th Marine Division on Roi-Namur, and the U. S. 7th Infantry Division on Kwajalein, resulted in a U. S. victory on 4 February 1944. The attack of the Japanese in the Marshall Islands was the first US attack, and capture, of Japanese territory, since the land was held by Japan before the start of World War II. The capture of Kwajalein Atoll during Operation Flintlock provided American forces with a base of operations that assured the recapture of the Philippines and eventually the fall of Japan.
Document 6: Manassas National Battlefield Park: Manassas National Battlefield Park, located north of Manassas, in Prince William County, Virginia, preserves the site of two major American Civil War battles: the First Battle of Bull Run on July 21, 1861, and the Second Battle of Bull Run which was fought between August 28 and August 30, 1862 (also known as the "First Battle of Manassas" and the "Second Battle of Manassas", respectively). The peaceful Virginia countryside bore witness to clashes between the armies of the North (Union) and the South (Confederacy), and it was there that Confederate General Thomas J. Jackson acquired his nickname "Stonewall."
Document 7: Battle of Thoroughfare Gap: The Battle of Thoroughfare Gap, also known as Chapman's Mill, took place on August 28, 1862, in Fauquier County and Prince William County, Virginia, as part of the Northern Virginia Campaign of the American Civil War. Confederate forces under Maj. Gen. James Longstreet successfully drove back Union forces under Brig. Gen. James B. Ricketts and Col. Percy Wyndham, allowing his corps to unite with that of Thomas J. "Stonewall" Jackson prior to the Second Battle of Bull Run (Second Manassas).
Document 8: Battle of Okinawa: The Battle of Okinawa (Japanese: 沖縄戦 , Hepburn: Okinawa-sen ) (Okinawan: 沖縄戦 , "Uchinaa ikusa " ), codenamed Operation Iceberg, was a major battle of the Pacific War fought on the island of Okinawa by United States Marine and Army forces against the Imperial Japanese Army and included the largest amphibious assault in the Pacific War during World War II, the April 1, 1945, invasion of Okinawa itself. The 82-day battle lasted from April 1 until June 22, 1945. After a long campaign of island hopping, the Allies were planning to use Okinawa, a large island only 340 mi away from mainland Japan, as a base for air operations for the planned invasion of the Japanese home islands.
Document 9: Attack on Pearl Harbor: The attack on Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service against the United States naval base at Pearl Harbor, Hawaii Territory, on the morning of December 7, 1941. The attack, also known as the Battle of Pearl Harbor, led to the United States' entry into World War II. The Japanese military leadership referred to the attack as the Hawaii Operation and Operation AI, and as Operation Z during its planning.
Document 10: Second Battle of Bull Run: The Second Battle of Bull Run or Battle of Second Manassas was fought August 28–30, 1862 in Prince William County, Virginia, as part of the American Civil War. It was the culmination of the Northern Virginia Campaign waged by Confederate Gen. Robert E. Lee's Army of Northern Virginia against Union Maj. Gen. John Pope's Army of Virginia, and a battle of much larger scale and numbers than the First Battle of Bull Run (or "First Manassas") fought on July 21, 1861 on the same ground.
Document 11: Battle of Peleliu: The Battle of Peleliu, codenamed Operation Stalemate II by the United States military, was fought between the U.S. and the Empire of Japan during the Mariana & Palau Campaign of World War II, from September to November 1944, on the island of Peleliu.
Document 12: Battle of Iwo Jima: The Battle of Iwo Jima (19 February – 26 March 1945) was a major battle in which the United States Marine Corps landed on and eventually captured the island of Iwo Jima from the Imperial Japanese Army during World War II. The American invasion, designated Operation Detachment, had the goal of capturing the entire island, including the three Japanese-controlled airfields (including the South Field and the Central Field), to provide a staging area for attacks on the Japanese main islands. This five-week battle comprised some of the fiercest and bloodiest fighting of the Pacific War of World War II.
Document 13: Guadalcanal Campaign: The Guadalcanal Campaign, also known as the Battle of Guadalcanal and codenamed Operation Watchtower was a military campaign fought between 7 August 1942 and 9 February 1943 on and around the island of Guadalcanal in the Pacific theater of World War II. It was the first major offensive by Allied forces against the Empire of Japan.
Document 14: Second Bull Run Union order of battle: The following Union Army units and commanders fought in the Second Battle of Bull Run of the American Civil War. The Confederate order of battle is listed separately. Order of battle compiled from the army organization during the battle, the casualty returns and the reports.
Document 15: Battle of Chantilly: The Battle of Chantilly (or Ox Hill, the Confederate name) took place on September 1, 1862, in Fairfax County, Virginia, as the concluding battle of the Northern Virginia Campaign of the American Civil War. Thomas J. "Stonewall" Jackson's corps of the Army of Northern Virginia attempted to cut off the line of retreat of the Union Army of Virginia following the Second Battle of Bull Run but was attacked by two Union divisions. During the ensuing battle, Union division commanders Isaac Stevens and Philip Kearny were both killed but the Union attack halted Jackson's advance.
ground_truth: Battle of Okinawa