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 john makes a contribution to a charity fund at school, the average contribution size will increase by 50 % reaching $ 75 per person. if there were 1 other contributions made before john ' s, what is the size of his donation ?
Options: a. $ 100, b. $ 150, c. $ 200, d. $ 250, e. $ 450

Output: a


Input: Consider Input: Problem: if a man lost 8 % by selling oranges at the rate of 25 a rupee at how many a rupee must he sell them to gain 25 % ?
Options: a. 20, b. 15, c. 18.4, d. 20, e. 12.8

Output: c


Input: Consider Input: Problem: in a village of 2,500 people, 800 people are over 70 years old and 850 people are female. it is known that 40 percent of the females are younger than 70 years old. if no one in the village is 70 years old, what is the probability that a person chosen at random is either a male or younger than 70 years old ?
Options: a. 221 / 250, b. 199 / 250, c. 33 / 50, d. 8 / 25, e. 51 / 250


Output: b