Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Ex Input:
Problem: a can give b 100 meters start and c 200 meters start in a kilometer race. how much start can b give c in a kilometer race ?
Options: a. 111.12 m, b. 221.12 m, c. 271.12 m, d. 611.12 m, e. 191.12 m

Ex Output:
a


Ex Input:
Problem: 6 men and 8 women can complete a work in 10 days. 26 men and 48 women can finish the same work in 2 days. 15 men and 20 women can do the same work in - days.
Options: a. 4 days, b. 6 days, c. 2 days, d. 8 days, e. 10 days

Ex Output:
a


Ex Input:
Problem: a man, a woman and a boy can together complete a piece of work in 3 days. if a woman alone can do it in 6 days and a boy alone in 18 days, how long will a man take to complete the work ?
Options: a. 5 days, b. 8 days, c. 7 days, d. 9 days, e. 8 days

Ex Output:

d