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.

Problem: there are 7 pairs of socks and 2 socks are worn from that such that the pair of socks worn are not of the same pair. what is the number of pair that can be formed.
Options: a. 40, b. 49, c. 41, d. 56, e. 42
e

Problem: in a fuel station the service costs $ 1.65 per car, every liter of fuel costs 0.65 $. assuming that a company owns 12 cars and that every fuel tank contains 55 liters and they are all empty, how much money total will it cost to fuel all cars ?
Options: a. 320 $, b. 380 $, c. 420 $, d. 448.8 $, e. 480 $
d

Problem: if p is the product of the integers from 1 to 36, inclusive, what is the greatest integer k for which 3 ^ k is a factor of p ?
Options: a. 13, b. 15, c. 17, d. 19, e. 21

c