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.

Example Input: Problem: find the sum of first 89 odd numbers
Options: a. 7921, b. 4800, c. 7900, d. 4980, e. 4960
Example Output: a

Example Input: Problem: if the price of a certain computer increased 30 percent from b dollars to 351 dollars, then 2 b =
Options: a. 540, b. 570, c. 619, d. 649, e. 700
Example Output: a

Example Input: Problem: how many positive integers between 1 and 200 are there such that they are multiples of 17 ?
Options: a. 9, b. 11, c. 13, d. 10, e. 8
Example Output:
b