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: one pipe can fill a tank three times as fast as another pipe. if together the two pipes can fill the tank in 34 minutes, then the slower pipe alone will be able to fill the tank in
Options: a. 144 mins, b. 140 mins, c. 136 mins, d. 132 minw, e. none of these
c