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.

Example Input: Problem: if a ' s height is 40 % less than that of b, how much percent b ' s height is more than that of a ?
Options: a. 66.66 %, b. 66.68 %, c. 66.766 %, d. 86.66 %, e. 66.65 %
Example Output: a

Example Input: Problem: a batsman makes a score of 87 runs in the 17 th inning and thus increases his average by 3. find his average after 17 th inning.
Options: a. 39, b. 88, c. 26, d. 87, e. 11
Example Output: a

Example Input: Problem: vishal invested 10 % more than trishul. trishul invested 10 % less than raghu. if the total sum of their investments is rs. 6358, how much amount did raghu invest ?
Options: a. 1287, b. 2200, c. 2000, d. 1129, e. 1192
Example Output:
b