Definition: 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: Problem: if p and q are positive integers each greater than 1, and 17 ( p + 1 ) = 21 ( q + 1 ), what is the least possible value of p + q ?
Options: a. 36, b. 42, c. 44, d. 46, e. none
Output:
a