Definition: 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: Question: Find the remainder when 2^31 is divided by 5.

 Option A: 3

 Option B: 7

 Option C: 1

 Option D: 9

 Option E: None of them

Option A