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: Read the following three equations:
5 ~ 4 ~ 3 ~ 9 = 4215
6 ~ 9 ~ 2 ~ 6 = 3816
4 ~ 7 ~ 3 ~ 3 = 1122
Now based on the rule that has been used, solve the following equation:
4 ~ 2 ~ 7 ~ 4 = ____

 Option A: 1416

 Option B: 2910

 Option C: 2940

 Option D: 3749

 Option E: 4470
Example Output: Option A

Example 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
Example Output: Option C

Example Input: Question: A can do a job in 30days and B in 40days. If they work on it together for 10 days, then the fraction of the work that is left is?

 Option A: 2/11

 Option B: 3/13

 Option C: 5/12

 Option D: 7/10

 Option E: 6/15
Example Output:
Option C