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

Output: a


Input: Consider Input: Problem: a cement mixture is composed of 3 elements. by weight, 1 / 2 of the mixture is sand, 1 / 5 of the mixture is water, and the remaining 15 pounds of the mixture is gravel. what is the weight of the entire mixture in pounds ?
Options: a. 30, b. 40, c. 50, d. 60, e. 80

Output: c


Input: Consider Input: Problem: a string of 30 light bulbs is wired in such a way that if any individual light bulb fails, the entire string fails. if for each individual light bulb the probability of failing during time period t is 0.1, what is the probability that the string of light bulbs will fail during the time period t ?
Options: a. 0.1, b. ( 0.1 ) ^ 30, c. 1 - ( 0.1 ) ^ 30, d. ( 0.93 ) ^ 30, e. 1 - ( 0.90 ) ^ 30


Output: e