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 soccer team played 280 games and won 65 percent of them. how many games did it win ?
Options: a. 182, b. 100, c. 104, d. 150, e. 124

Ex Output:
a


Ex Input:
Problem: for the past n days, the average ( arithmetic mean ) daily production at a company was 50 units. if today ' s production of 110 units raises the average to 55 units per day, what is the value of n ?
Options: a. 9, b. 11, c. 13, d. 15, e. 17

Ex Output:
b


Ex Input:
Problem: a can do a job in 9 days and b can do it in 27 days. a and b working together will finish twice the amount of work in - - - - - - - days ?
Options: a. 22 days, b. 18 days, c. 22 6 / 2 days, d. 27 days, e. 9 days

Ex Output:

b