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: the diagonal of a rectangle is √ 41 cm and its area is 20 sq. cm. the perimeter of the rectangle must be :
Options: ['a. 18', 'b. 28', 'c. 38', 'd. 48', 'e. 58']

Ex Output:
a


Ex Input:
Problem: ramesh purchased a refrigerator for rs. 12500 after getting a discount of 20 % on the labelled price. he spent rs. 125 on transport and rs. 250 on installation. at what price should it be sold so that the profit earned would be 18 % if no discount was offered ?
Options: a. 17608, b. 17606, c. 17604, d. 17600, e. 18880

Ex Output:
e


Ex Input:
Problem: the speed at which a man can row a boat in still water is 22 kmph. if he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 80 metres ?
Options: a. 12.59, b. 11.53, c. 15.69, d. 14.56, e. 18.98

Ex Output:

b