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 cost of 8 dozen pencil and 2 dozen note book is 520 rupee. if cost of 3 pencil and 4 note book is 60 rupee, then sum of the cost of 1 pencil and 1 note book will be ( in rupee.
Options: a. rs 13.51, b. rs 15.51, c. rs 16.51, d. rs 14.51, e. rs 17.51

Output: b


Input: Consider Input: Problem: 54671 - 14456 - 31466 = ?
Options: a. 2449, b. 5449, c. 8749, d. 8449, e. 6468

Output: c


Input: Consider Input: Problem: two pipes can fill the cistern in 10 hr and 12 hr respectively, while the third empty it in 30 hr. if all pipes are opened simultaneously, then the cistern will be filled in
Options: a. 6.67 hr, b. 8 hr, c. 8.5 hr, d. 10 hr, e. none of these


Output: a