Q: 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.
Question: 20, 19, 17, ?, 10, 5

 Option A: 15

 Option B: 14

 Option C: 13

 Option D: 12

 Option E: 11
A:
Option B