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: What is the next number of the following sequence
3,7,13,21,?

 Option A: 22

 Option B: 31

 Option C: 41

 Option D: 35

 Option E: 42

Option B