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: 8 persons can build a wall 140m long in 42 days. In how many days can 30 persons complete a similar wall 100 m long?

 Option A: 12

 Option B: 10

 Option C: 8

 Option D: 6

 Option E: 5

Ex Output:
Option C


Ex Input:
Question: On dividing 21 by a number, the quotient is 10 and the remainder is 1. Find the divisor.

 Option A: 1

 Option B: 2

 Option C: 4

 Option D: 6

 Option E: 7

Ex Output:
Option B


Ex Input:
Question: If a farmer wants to plough a farm field on time, he must plough 120 hectares a day. For technical reasons he ploughed only 85 hectares a day, hence he had to plough 2 more days than he planned and he still has 40 hectares left. What is the area of the farm field and how many days the farmer planned to work initially?

 Option A: 600

 Option B: 490

 Option C: 720

 Option D: 435

 Option E: 679

Ex Output:

Option C