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: last year elaine spent 20 % of her annual earnings on rent. this year she earned 35 % more than last year and she spent 30 % of her annual earnings on rent. the amount she spent on rent this year is what percent of the amount spent on rent last year ?
Options: a. 202.5, b. 194.5, c. 197.5, d. 182.5, e. 177.5

Ex Output:
a


Ex Input:
Problem: the average score of a cricketer in 2 matches is 30 and in other 3 matches is 40. then find the average score in all the 5 matches ?
Options: a. 25, b. 27, c. 30, d. 35, e. 36

Ex Output:
e


Ex Input:
Problem: the base and height of a parallelogram are 12 m and 6 m respectively. then its area is = = = = = = ?
Options: ['a. 27 sq. m', 'b. 126 sq. m', 'c. 84 sq. m', 'd. 18 sq. m', 'e. 72 sq. m']

Ex Output:

e