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.

Input: Consider Input: Problem: if a sum of money doubles itself in 20 years at simple interest, the ratepercent per annum is
Options: a. 12, b. 12.5, c. 13, d. 5, e. 14

Output: d


Input: Consider Input: Problem: what is the smallest positive integer x such that 66 - x is the cube of a positive integer
Options: a. 5, b. 7, c. 47, d. 9, e. 2

Output: e


Input: Consider Input: Problem: in a government institute 20 nos. staffs are employed. in a festival season their boss give festival allowance to all. he says his accountant to calculate for 30 days @ 100. also he says balance payment will give to driver and cleaning staff and to be adjust from petty cash. he had given rs. 65000 / - to the accountant. how much amount will taken from petty cash ?
Options: a. a. 1000, b. b. 3000, c. c. 3500, d. d. 2500, e. e. 2250


Output: a