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.

Ex Input:
Problem: trapezoid jklm in the x - y plane has coordinates j = ( 3, 4 ), k = ( 3, 1 ), l = ( 5, 7 ), and m = ( 5, 4 ). what is its perimeter ?
Options: a. 34, b. 36, c. 38, d. 40, e. ( f ) 42

Ex Output:
a

Ex Input:
Problem: of 30 applicants for a job, 9 had at least 4 years ' experience, 18 had degrees, and 3 had less than 4 years ' experience and did not have a degree. how many of the applicants had at least 4 years ' experience and a degree ?
Options: a. 14, b. 10, c. 9, d. 7, e. 5

Ex Output:
b

Ex Input:
Problem: a store reduced the price of all items in the store by 10 % on the first day and by another 10 % on the second day. the price of items on the second day was what percent of the price before the first reduction took place ?
Options: a. 80.0, b. 80.9, c. 81.0, d. 81.1, e. 81.9

Ex Output:
c