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: the price of a certain painting increased by 30 % during the first year and decreased by 15 % during the second year. the price of the painting at the end of the 2 - year period was what percent of the original price ?
Options: a. 102 %, b. 105 %, c. 110.5 %, d. 112.5 %, e. 100 %

Ex Output:
c


Ex Input:
Problem: if a lends rs. 3150 to b at 8 % per annum and b lends the same sum to c at 12.5 % per annum then the gain of b in a period of 2 years is ?
Options: a. 280, b. 295, c. 283.5, d. 245, e. 200

Ex Output:
c


Ex Input:
Problem: a part of certain sum of money is invested at 16 % per annum and the rest at 20 % per annum, if the interest earned in each case for the same period is equal, then ratio of the sums invested is ?
Options: a. 4: 6, b. 4: 9, c. 4: 3, d. 4: 1, e. 5: 4

Ex Output:

e