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.

Ex 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

Ex Output:
c


Ex Input:
Problem: a cricketer whose bowling average is 12.4 runs per wicket takes 5 wickets for 26 runs and there by decreases his average by 0.4. the number age of the family now is :
Options: a. 18, b. 17, c. 76, d. 85, e. 86

Ex Output:
d


Ex Input:
Problem: the mean of 50 observations is 200. but later he found that there is decrements of 6 from each observations. what is the the updated mean is ?
Options: a. 165, b. 185, c. 190, d. 198, e. 194

Ex Output:

e