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: If f(y)=y^2 and y is a positive integer, which of the following CANNOT be the value of f(f(y))?

Option A: 1

Option B: 144

Option C: 81

Option D: 16

Option E: 256

Output: Option B

Input: Consider Input: Question: If k and w are the dimensions of a rectangle that has area 21, and if k and w are integers such that k > w, what is the total number of possible values of k?

Option A: Two

Option B: Three

Option C: Four

Option D: Five

Option E: Six

Output: Option A

Input: Consider Input: Question: A train , having a length of 275 meter is running at a speed of 60 kmph. In what time, it will pass a man who is running at 6 kmph in the direction opposite to that of the train

Option A: 10 sec

Option B: 8 sec

Option C: 15 sec

Option D: 4 sec

Option E: 2 sec
Output: Option C