You will be given a definition of a task first, then some input of the task.
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: What are the other names of two-seat night fighter planes used by the Royal Air Force? Passage:The Venom entered service with the Royal Air Force (RAF), where it was used as a single-seat fighter-bomber and two-seat night fighter. A dedicated model for aerial reconnaissance was also operated by the Swiss Air Force. The Venom functioned as an interim stage between the first generation of British jet fighters straight-wing aircraft powered by centrifugal flow engines such as the Gloster Meteor and the Vampire and later swept wing, axial flow-engined combat aircraft, such as the Hawker Hunter and de Havilland Sea Vixen. Accordingly, the type had a relatively short service life in the RAF, being withdrawn from frontline operations by the service in 1962 as a result of the introduction of more capable designs. However, it was used in combat during the Suez Crisis, the Malayan Emergency, and the Aden Emergency.
Links: a. Night fighter b. Swiss Air Force c. Suez Crisis d. Centrifugal compressor
Output:
a