Explanation

Don’t do the arithmetic! These are common quadratic patterns.

It’s not important that x = 141 and y = 28;

Quantity A is $x^2 - y^2 = (x + y)(x - y)$, and

Quantity B is $(x - y)(x - y).$

Since (x – y) is a positive number, you can simply compare the remaining factors after it is removed from both quantities. Since x and y are positive, (x + y) is greater than the
remaining (x – y) in Quantity B, and the answer is choice (A).