You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

Input: Consider Input: Question: A and B together can do a work in 3 days. If A alone can do it in 12 days. In how many days can B alone do it?

Option A: 4

Option B: 6

Option C: 8

Option D: 10

Option E: 25

Output: Option A

Input: Consider Input: Question: One water pump can fill half of a certain empty tank in 7 hours. Another pump can fill half of the same tank in 7.5 hours. Working together, how long will it take these two pumps to fill the entire tank?

Option A: 7 7/13

Option B: 1 5/8

Option C: 3 1/4

Option D: 7 7/29

Option E: 3 1/2

Output: Option D

Input: Consider Input: Question: Each of the 11 letters A, H, I, M, O, T, U, V, W, X and Z appears same when looked at in a mirror. They are called symmetric letters. Other letters in the alphabet are asymmetric letters. How many two letter computer passwords can be formed (no repetition allowed) with at least one symmetric letter?

Option A: 2,420

Option B: 6,435

Option C: 12,100

Option D: 12,870

Option E: 25,740
Output: Option A