Given the task definition and input, reply with output. In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

Question: In what year was the Battle of Leyte Gulf? Passage:On 20 October, D-Day for the Leyte landing forces, Mertz escorted landing craft through air attacks to the beach and later in the day patrolled off Dinagat Island at the entrance to Leyte Gulf. Early in the morning of 25 October as the Japanese Southern Force approached Leyte Gulf through the Mindanao Sea, Mertz and patrolled between Desolation Point and Homonhon Island, lest the enemy fleet choose to steam north along the east coast of Dinagat Island to attack the Allied beachhead. When the Japanese entered Surigao Strait, Rear Admiral Jesse B. Oldendorf's force met and destroyed the enemy armada in the classic "crossing-of-the-T" maneuver known as the Battle of Surigao Strait, part of the overall Battle of Leyte Gulf. Later that same day Mertz splashed a Zero at several hundred yards with heavy machinegun fire.
Links: a. Allies of World War II b. Battle of Leyte Gulf c. Allies of World War II d. Dinagat Island
b