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.

Example Input: Question: Two stations A and B are 20 km apart on a straight line. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?

 Option A: 9

 Option B: 10

 Option C: 11

 Option D: 12

 Option E: 8
Example Output: Option E

Example Input: Question: x% of y is y% of ?

 Option A: x

 Option B: 100x

 Option C: x/100

 Option D: y/100

 Option E: None
Example Output: Option A

Example Input: Question: If 625^(-x) + 25^(-2x) + 5^(-4x) = 10, what is the value of x?

 Option A: -4

 Option B: -1/4

 Option C: 0

 Option D: 1/4

 Option E: 4
Example Output:
Option C