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: if a person walks at 25 km / hr instead of 10 km / hr, he would have walked 20 km more. the actual distance traveled by him is :
Options: a. 50 km, b. 56 km, c. 13.3 km, d. 70 km, e. 80 km
Example Output: c

Example Input: Problem: an 80 - liter solution of cool - drink is made from 10 % jasmine water. if 5 liters of jasmine and 15 liters of water were added to the solution, what percent of the solution is jasmine ?
Options: a. 11 %, b. 13 %, c. 15 %, d. 17 %, e. 19 %
Example Output: b

Example Input: Problem: the least number which should be added to 1789 so that the sum is exactly divisible by 5, 6, 4 and 3 is ?
Options: a. 1, b. 11, c. 21, d. 31, e. 41
Example Output:
b