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: 23, 18, 16, 11, 9, 4 ?

 Option A: 3

 Option B: 2

 Option C: 7

 Option D: 5

 Option E: 1
Example Output: Option B

Example Input: Question: Every year an amount increases by 1/8th of itself. How much will it be after two years if its present value is Rs.1600?

 Option A: 3000

 Option B: 4200

 Option C: 2025

 Option D: 1205

 Option E: 3251
Example Output: Option C

Example Input: Question: A vessel contains 20 liters of a mixture of milk and water in the ratio 3:2. 10 liters of the mixture are removed and replaced with an equal quantity of pure milk. If the process is repeated once more, find the ratio of milk and water in the final mixture obtained?

 Option A: 9:1

 Option B: 4:7

 Option C: 7:1

 Option D: 2:5

 Option E: 5:6
Example Output:
Option A