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: if the perimeter of a rectangular garden is 700 m, its length when its breadth is 100 m is ?
Options: a. 299 m, b. 777 m, c. 200 m, d. 250 m, e. 128 m
[EX A]: d

[EX Q]: Problem: what is the greatest positive integer n such that 3 ^ n is a factor of 36 ^ 100 ?
Options: a. 100, b. 200, c. 300, d. 600, e. 900
[EX A]: b

[EX Q]: Problem: if the product of the integers w, x, y and z is 840, and if 1 < w < x < y < z, what is the value of w + z ?
Options: a. 10, b. 11, c. 16, d. 18, e. 21
[EX A]:
b