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 van takes 5 hours to cover a distance of 495 km. what speed in kph should the van maintain to cover the same distance in 3 / 2 of the previous time ?
Options: a. 60, b. 63, c. 66, d. 69, e. 72

Output: c

Input: Consider Input: Problem: 40 is subtracted from 60 % of a number, the result is 50. find the number ?
Options: a. 150, b. 330, c. 277, d. 279, e. 712

Output: a

Input: Consider Input: Problem: find the probability that the number drawn is a multiple of 6 and 8.
Options: a. 3 / 50, b. 2 / 25, c. 1 / 50, d. 1 / 25, e. 4 / 25
Output: d