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: a train 510 m long is running at a speed of 45 km / hr. in what time will it pass a bridge 140 m long ?
Options: a. 40, b. 52, c. 26, d. 21, e. 14
Example Output: b

Example Input: Problem: 10, 1000, 100000, 10000000....
Options: a. 100, 000,000, b. 1,000, 000,000, c. 1, 000,000, 000,000, d. 100, e. 1, 000,000
Example Output: b

Example Input: Problem: you enter a weight loss challenge game and manage to lose 12 % of your body weight. for the final weigh in you are forced to wear clothes that add 2 % to your weight. what percentage of weight loss is measured at the final weigh in ?
Options: a. 10.24 %, b. 9.22 %, c. 9 %, d. 14 %, e. 12 %
Example Output:
a