Question: No.11 Group was a part of which air force that emerged as the largest air force in the world in 1918?

Context paragraphs:
Royal Air Force: The Royal Air Force (RAF) is the United Kingdom's aerial warfare force.  Formed towards the end of the First World War on 1 April 1918, it is the oldest independent air force in the world.  Following victory over the Central Powers in 1918 the RAF emerged as, at the time, the largest air force in the world.  Since its formation, the RAF has taken a significant role in British military history, in particular, playing a large part in the Second World War where it fought its most famous campaign, the Battle of Britain.

George G. Finch: Maj. Gen. George G. Finch became the Senior Leader of the US Air National Guard; (Chief of the Air Division National Guard Bureau) (1948-1950) In June 1953 it was reported that Gen. Mark W. Clark would retire and be replaced by Maj. Gen George G. Finch on the UN command delegation to the Korean armistice talks George G. Finch, born April 11, 1902 in Dade City, Florida, is considered one of the pioneers in United States aviation history.  He began his military career during World War 1, enlisting in the Aviation Section of the Army's Signal Corps in 1918.  He remained in the Reserve Corps after the war, and in 1926, became Commander, 27th Pursuit Squadron, 1st Pursuit Group.  In 1940, Georgia Governor Ed Rivers commissioned him to form the first flying unit of the Georgia Air National Guard.  The unit was mobilized into the U.S. Army in September, 1941, with Major Finch as commander.  After World War II, he was a leading critic of efforts to eliminate the air arm of the National Guard during peacetime.  General Finch gained the respect and admiration of Air National Guardsmen throughout the nation with his steadfast support and successful efforts to preserve the Air Guard.  He became the first Chief of the Air Force Division of the National Guard Bureau in 1948.  Under his leadership, the Air National Guard built to combat readiness and was among the first components called into service after the outbreak of the Korean War.  As a result of General Finch's vision and perseverance, 45,000 highly trained officers and airmen of 22 wings and 65 squadrons gave the Air Force the strength it needed in the early, critical phases of the Communist drive down the Korean peninsula.General Finch served as the senior Air Force member of the United Nations negotiating team at the peace talks at Panmunjom, Korea, and received the Legion of Merit for outstanding service in 1955; General Finch assumed command of Fourteenth Air Force, Robins AFB, Georgia, becoming the nation's first Air National Guardsman to head a numbered air force.  General Finch had a career of "firsts" including the US Army's first night landing with a single, five-million-candlepower floodlight in 1927.  He also established and endowed the General John P. McConnell Award at the United States Air Force Academy.  Considered by many as the father of the strong, independent Air National Guard existing today, General Finch retired in 1957.  No man has had greater impact on the Air Force Reserve and National Guard than has General George G. Finch.A graduate of the University of Georgia and a member of the Georgia Bar, General Finch was enshrined in the Georgia Aviation Hall of Fame May 18, 1996.

Hindon Air Force Station: Air Force Station Hindon (Hindon AFS) (also Hindan) is an Indian Air Force base under the Western Air Command (WAC).  It is the biggest and largest air base in Asia and 8th in the world.  Its area measured 14 km rounded and 55 km2 .  This base celebrates Air Force Day on 8 October.  It is located near Loni Ghaziabad in the state of Uttar Pradesh in the National Capital Region on the outskirts of Delhi, close to the Hindan River.  Starting 2006, the annual Air Force Day Parade venue was shifted from Palam Airport to Hindan.  There is one runway, aligned east-west (09-27), of 9000 ft length x 150 ft width.  This is the home of the C-17 Globemaster the backbone of Heavy Air Lift division of Indian Air Force

Desert Air Force: The Desert Air Force (DAF), also known chronologically as Air Headquarters Western Desert, Air Headquarters Libya, the Western Desert Air Force, and the First Tactical Air Force (1TAF), was an Allied tactical air force created from No. 204 Group under RAF Middle East Command in North Africa in 1941 to provide close air support to the British Eighth Army.  Throughout World War II, the DAF was made up of squadrons from the Royal Air Force (RAF), the South African Air Force (SAAF), the Royal Australian Air Force (RAAF), the United States Army Air Forces (USAAF) and other Allied air forces.

Yugoslav Air Force: The Yugoslav Air Force (Serbian: Југословенско Ратно ваздухопловство и противваздушна одбрана, Slovenian: Jugoslovansko vojno letalstvo, Croatian: Jugoslavensko ratno zrakoplovstvo i protuzračna obrana) was the air force of Yugoslavia, and functioned as one of three branches of the military, the Yugoslav People's Army (JNA).  The official name of the branch was Air Force and Anti-Air Defence (Ратно ваздухопловство и противваздушна одбрана, РВ и ПВО; "Ratno zrakoplovstvo i protuzračna obrana", RZ i PZO; Croatian name has never been used).  At its height, it was one of the largest air forces in Europe.  The Yugoslav Air Force was disbanded following the dissolution of Yugoslavia 1991-1992.

German Air Force: The German Air Force (German: "Luftwaffe" (] ), the German-language generic term for "air force") is the aerial warfare branch of the Bundeswehr, the armed forces of Germany.  With a strength of 28,448 personnel (28 February 2017), it is the fourth largest air force within the European Union, after the air forces of the United Kingdom, France and Italy.  Although its budget has been significantly reduced since the end of the Cold War in 1989–1990, the Luftwaffe is still among the best-equipped air forces of the world.

Exercise Redoubt Condor: Exercise Redoubt Condor was a United States Air Force Reserve exercise that occurred in 1981 and was headquartered at Westover Air Reserve Base.  It was designed to be a continuation of Operation Redoubt, a series of exercises that tested the mobilization capabilities of the Air Force Reserve.  It was the largest mobilization of the Air Force Reserve in its history.  Redoubt Condor culminated in 1981 by being the largest Air Force Reserve mobilization at the time.

March Air Reserve Base: March Air Reserve Base (IATA: RIV, ICAO: KRIV, FAA LID: RIV) (March ARB), previously known as March Air Force Base (March AFB) is located in Riverside County, California between the cities of Riverside and Moreno Valley.  It is the home to the Air Force Reserve Command's 4th Air Force (4 AF) Headquarters and the host 452d Air Mobility Wing (452 AMW), the largest air mobility wing of the 4th Air Force.  In addition to multiple units of the Air Force Reserve Command supporting Air Mobility Command, Air Combat Command and Pacific Air Forces, March ARB is also home to units from the Army Reserve, Navy Reserve, Marine Corps Reserve, California Air National Guard and the California Army National Guard.  For almost 50 years, March AFB was a Strategic Air Command base during the Cold War.

No. 11 Group RAF: No. 11 Group was a group in the Royal Air Force for various periods in the 20th century, finally disbanding in 1996.  Its most famous service was during 1940 when it defended London and the south-east against the attacks of the Luftwaffe during the Battle of Britain.

Brazilian Air Force Academy: The Brazilian Air Force Academy (AFA, "Academia da Força Aérea" in Portuguese) is the Brazilian Air Force's educational institution that provides initial officer training for the main Officer Board of Brazil's Air Force Command.  The Academy is located east of Pirassununga city, in São Paulo State county, and it is the largest Brazilian Air Base as well as the largest Air Force Academy of Latin America.  All three Officer Formation Courses (CFOs) of "Academia da Força Aérea" are recognized as Superior Degree by Brazil's Ministry of Educations.

Supporting paragraphs: No. 11 Group RAF Royal Air Force
Answer: The Royal Air Force