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: if a / b = 4 / 3, then ( 3 a + 2 b. / ( 3 a - 2 b. = ?
Options: a. 6, b. 3, c. 5, d. - 1, e. none

Ex Output:
b


Ex Input:
Problem: if 8 men or 12 women can do a piece of work in 30 days, in how many days can the same work be done by 6 men and 11 women ?
Options: a. 10 days, b. 11 days, c. 13 days, d. 15 days, e. 18 days

Ex Output:
e


Ex Input:
Problem: the average temperature for tuesday, wednesday and thursday was 42 ° c. the average temperature for wednesday, thursday and friday was 44 ° c. if the temperature on friday be 43 ° c, what was the temperature on tuesday ?
Options: a. 39 ° c, b. 44 ° c, c. 37 ° c, d. 42 ° c, e. none of these

Ex Output:

c