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 perimeter of a triangle is 40 cm and the inradius of the triangle is 2.5 cm. what is the area of the triangle ?
Options: a. 87 cm 2, b. 28 cm 2, c. 98 cm 2, d. 26 cm 2, e. 50 cm 2

Ex Output:
e


Ex Input:
Problem: at what price must an article costing rs. 47.50 be marked in order that after deducting 7 % from the list price. it may be sold at a profit of 25 % on the cost price ?
Options: a. 63.84, b. 62.6, c. 62.1, d. 62.7, e. 62.2

Ex Output:
a


Ex Input:
Problem: how many integers n are prime numbers in the range 200 < n < 220 ?
Options: a. 1, b. 2, c. 3, d. 4, e. 5

Ex Output:

a