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: Consider Input: Question: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?

 Option A: 6 kmph

 Option B: 9 kmph

 Option C: 3 kmph

 Option D: 8 kmph

 Option E: 1 kmph

Output: Option D


Input: Consider Input: Question: The original price of a shirt was $20. It was decreased to $15 . What is the percent decrease of the price of this shirt.

 Option A: 25%

 Option B: 35%

 Option C: 45%

 Option D: 55%

 Option E: 65%

Output: Option A


Input: Consider Input: Question: A and B can together finish a work in 40days. They worked together for 10days and then B left. After another 12days, A finished the remaining work. In how many days A alone can finish the job?

 Option A: 10

 Option B: 25

 Option C: 60

 Option D: 16

 Option E: 20


Output: Option D