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.

[Q]: Problem: what is the smallest positive integer x such that 66 - x is the cube of a positive integer
Options: a. 5, b. 7, c. 47, d. 9, e. 2
[A]: e


[Q]: Problem: what is the units digit of 26 ! + 50 ! + 4 ! + 4 ! ?
Options: a. 8, b. 6, c. 4, d. 2, e. 0
[A]: a


[Q]: Problem: in x game of billiards, x can give y 20 points in 60 and he can give z 30 points in 60. how many points can y give z in x game of 120 ?
Options: a. 30, b. 20, c. 25, d. 40, e. 50
[A]:
a