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.

Example Input: Problem: 30 pens and 75 pencils were purchased for 750. if the average price of a pencil was 2.00, find the average price of a pen.
Options: a. 20, b. 11, c. 12, d. 13, e. 14
Example Output: a

Example Input: Problem: cathy and jim begin running at the same time and they start at the same place on a straight path. cathy runs at 10 miles per hour, and jim runs at 6 miles per hour. after 18 minutes, cathy stops to stretch. if it takes cathy 27 minutes to stretch and jim continues to run during this time, how many minutes will it take cathy to catch up to jim ?
Options: a. 20.5, b. 21.5, c. 22.5, d. 23.5, e. 24.5
Example Output: c

Example Input: Problem: initially, the men and women in a room were in the ratio of 4: 5. then, 2 men entered the room and 3 women left the room. then, the number of women doubled. now there are 14 men in the room. how many w women are currently in the room ?
Options: a. 12, b. 14, c. 15, d. 24, e. 36
Example Output:
d