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: If the operation ∆ is defined by a ∆ b = (b - a)^2/a^2 for all numbers a and b, and a ≠ 0, then what is the result when we evaluate this expression: (-5) ∆ (5 ∆ −5) ?

 Option A: 49/9

 Option B: 49/16

 Option C: 81/16

 Option D: 81/25

 Option E: 100/81

Ex Output:
Option D


Ex Input:
Question: In what time will a railway train 90 m long moving at the rate of 44 kmph pass a telegraph post on its way?

 Option A: 3

 Option B: 5

 Option C: 4.3

 Option D: 6.5

 Option E: 7.4

Ex Output:
Option E


Ex Input:
Question: The tax on a commodity is diminished by 20% and its consumption increased by 15%. The effect on revenue is?

 Option A: 2%

 Option B: 8%

 Option C: 5%

 Option D: 6%

 Option E: 1%

Ex Output:

Option B