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: a, b, c can complete a piece of work in 24, 8,12 days. working together, they complete the same work in how many days ?
Options: a. 4, b. 4 / 5, c. 7 / 9, d. 10, e. 24 / 7

Output: a


Input: Consider Input: Problem: what least number must be subtracted from 13294 so that the remainder is exactly divisible by 97 ?
Options: a. 3, b. 5, c. 7, d. 9, e. 10

Output: b


Input: Consider Input: Problem: the pilot of a small aircraft with a 40 - gallon fuel tank wants to fly to cleveland, which is 480 miles away. the pilot recognizes that the current engine, which can fly only 6 miles per gallon, will not get him there. by how many miles per gallon must the aircraft ’ s fuel efficiency be improved to make the flight to cleveland possible ?
Options: a. 2, b. 4, c. 12, d. 6, e. 160


Output: d