You will be given a definition of a task first, then an example. Follow the example to solve a new instance 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: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin? Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Loduring July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Links: a. Allies of World War II b. Wesel c. Operation Market Garden d. Air Support.
Solution: c
Why? The passage describes the 704th's actions during Operation Market Garden.

New input: Question: When did construction begin on the Space Station launched in the 1970's based on a design of the Saturn IB S-IVB upper stage called Skylab A? Passage:In the 1970s, the Skylab Space Station is launched, but apparently as a wet workshop design that is based on the Saturn IB S-IVB upper stage called Skylab A. The Saturn V that might have launched Skylab in our timeline instead launches Skylab B, a lunar orbit space station unofficially named "Moonlab", also a wet workshop based on the S-IVB. The Apollo-Soyuz Test Project is instead a series of visits by the Apollo Command/Service Module to Salyut space stations, and Soyuz missions to both Skylab and Moonlab. To facilitate the latter, the Soviets finally finish work on their N-1. The Skylab/Moonlab programs lead to improvements in the design of the Apollo Command/Service Module. A Block III CSM is produced using battery power in place of fuel cells, followed by the Block IV and V, which have a degree of reusability (modular construction and resistance to salt water corrosion). Also chronicled is the development of the experimental 'Mars Excursion Module' by small aerospace firm Columbia Aviation as it struggles against larger rival contractors of NASA and its engineers working painstakingly against the technical challenges of a working and reliable Mars lander.
Links: a. Skylab b. S-IVB c. S-IVB d. ApolloSoyuz Test Project
Solution:
a