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.

Ex Input:
Question: A contractor undertakes to built a walls in 50 days. He employs 40 peoples for the same. However after 25 days he finds that only 40% of the work is complete. How many more man need to be employed to complete the work in time?

 Option A: 60

 Option B: 30

 Option C: 35

 Option D: 20

 Option E: None of these

Ex Output:
Option A


Ex Input:
Question: The population of a certain town increases by 50 percent every 50 years. If the population in 1950 was 810, in what year was the population 160?

 Option A: 1650

 Option B: 1700

 Option C: 1750

 Option D: 1800

 Option E: 1850

Ex Output:
Option C


Ex Input:
Question: If the operation € is defined for all x and y by the equation x € y = 3*x*y, then 3 € (4 € 5) =

 Option A: 80

 Option B: 120

 Option C: 160

 Option D: 540

 Option E: 660

Ex Output:

Option D