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 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: a person purchases 90 clocks and sells 40 clocks at a gain of 10 % and 50 clocks at a gain of 20 %. if he sold all of them at a uniform profit of 15 %, then he would have got rs. 40 less. the cost price of each clock is :
Options: a. 50, b. 90, c. 80, d. 28, e. 93

Ex Output:
c


Ex Input:
Problem: on the first of the year, james invested x dollars at proudstar bank in an account that yields 0.5 % in interest every quarter year. at the end of the year, during which he made no additional deposits or withdrawals, he had y dollars in the account. if james had invested the same amount in an account which pays interest on a yearly basis, what must the interest rate be for james to have y dollars at the end of the year ?
Options: a. 2.04 %, b. 4.12 %, c. 5 %, d. 8.25 %, e. 10 %

Ex Output:

a