Detailed Instructions: 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: a monkey ascends a greased pole 10 meters high. he ascends 2 meters in the first minute and then slips down 1 meter in the alternate minute. if this pattern continues until he climbs the pole, in how many minutes would he reach at the top of the pole ?
Options: a. 10 th minute, b. 21 st minute, c. 17 th minute, d. 22 nd minute, e. 13 th minute
A:
c