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: The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 kms in 4 hours, then the speed of the first train is:

 Option A: 70 km/hr

 Option B: 75 km/hr

 Option C: 84 km/hr

 Option D: 87.5 km/hr

 Option E: 88.5 km/hr

Output: Option D


Input: Consider Input: Question: What is the sum of all the numbers which divides 100 ?

 Option A: 408

 Option B: 102

 Option C: 816

 Option D: 916

 Option E: 416

Output: Option A


Input: Consider Input: Question: What is (21^7+21) / 21?

 Option A: 82216043

 Option B: 83786095

 Option C: 84316108

 Option D: 85766122

 Option E: 86426237


Output: Option D