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: A reduction of 20% in the price of salt enables a lady to obtain 10kgs more for Rs.100, find the original price per kg?

 Option A: Rs.3.2

 Option B: Rs.2.9

 Option C: Rs.2.5

 Option D: Rs.5.2

 Option E: Rs.2.1

Output: Option C


Input: Consider Input: Question: For positive integers x and z, which of the following can be written as z^2?

 Option A: x^2+1

 Option B: x^2-1

 Option C: x^2-24

 Option D: x^2+11

 Option E: x^2-11

Output: Option D


Input: Consider Input: Question: In how many years, Rs. 150 will produce the same interest at 6% as Rs. 800 produce in 2 years at 4½% ?

 Option A: 4 years

 Option B: 6 years

 Option C: 8 years

 Option D: 9 years

 Option E: 10 years


Output: Option C