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: the average of first five multiples of 7 is :
Options: a. 9, b. 16, c. 15, d. 8, e. 21

Output: e


Input: Consider Input: Problem: if the radius of a cylinder is made 3 times and so is the height, what is the new volume of the cylinder divided by the old one ?
Options: a. 27., b. 2., c. 6., d. 4., e. 10.

Output: a


Input: Consider Input: Problem: the principal that amounts to rs. 4813 in 3 years at 6 1 / 4 % per annum c. i. compounded annually, is ?
Options: a. s. 3096, b. s. 4036, c. s. 4085, d. s. 4096, e. s. 5096


Output: b