Definition: 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: Problem: fresh grapes contain 80 % water by weight and raisins obtained by drying fresh grapes contain 25 % water by weight. how many kgs of fresh grapes are needed to get 40 kgs of raisins ?
Options: a. 150 kgs, b. 64 kgs, c. 72 kgs, d. 65 kgs, e. 70 kgs
Output:
a