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.

Input: Consider Input: Problem: if the sides of a triangle are 26 cm, 24 cm and 15 cm, what is its area ?
Options: a. 120, b. 772, c. 180, d. 266, e. 2848

Output: c

Input: Consider Input: Problem: if n = 2 ^ 0.15 and n ^ b = 1, b must equal
Options: a. 3 / 80, b. 20 / 3, c. 4, d. 5 / 3, e. 80 / 3

Output: b

Input: Consider Input: Problem: the percentage increase in the area of a rectangle, if each of its sides is increased by 20 % is ?
Options: a. 44 %, b. 45 %, c. 50 %, d. 55 %, e. 60 %
Output: a