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: 2,7, 17,3, 11,19, 5,13, __
Options: a. 20, b. 21, c. 22, d. 23, e. 24

Output: d


Input: Consider Input: Problem: a mixture of 70 litres of milk and water contains 10 % water. how many litres of water should be added to the mixture so that the mixture contains 12 1 / 2 % water ?
Options: a. 2, b. 8, c. 6, d. 3, e. 4

Output: a


Input: Consider Input: Problem: if 2 + 2 / x = 3 - 3 / x, then x =
Options: a. - 5, b. 2 / 3, c. 1, d. 3 / 2, e. 5


Output: e