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: 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: The bankerâ€™s discount on Rs. 1600 at 10% per annum is the same as true discount on Rs. 1680 for the same time and at the same rate. The time is :

 Option A: 2 months

 Option B: 4 months

 Option C: 6 months

 Option D: 7 months

 Option E: None

Output: Option C


Input: Consider Input: Question: If the sum and difference of two numbers are 15 and 10 respectively, then the difference of their square is:

 Option A: 12

 Option B: 150

 Option C: 160

 Option D: 180

 Option E: 18


Output: Option B