Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

[EX Q]: Problem: the overall age of x and y is 19 year greater than the overall age of y and z. z is how many decades younger that x ?
Options: a. 11, b. 15, c. 12, d. 19, e. 20
[EX A]: d

[EX Q]: Problem: what is the smallest number by which 2880 must be divided in order to make it into a perfect square ?
Options: a. 3, b. 4, c. 5, d. 6, e. 7
[EX A]: c

[EX Q]: Problem: for every integer n ≥ 3, the function g ( n ) is defined as the product of all the odd integers from 1 to n, inclusive. what is the value of g ( 101 ) – g ( 99 ) ?
Options: a. 0, b. 98, c. 99, d. 100, e. 90
[EX A]:
d