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 statue is being carved by a sculptor. the original piece of marble weighed 180 kg. in the first week 28 percent is cut away. in the second week 18 percent of the remainder is cut away. in the third week the statue is completed when 20 percent of the remainder is cut away. what is the weight of the final statue ?
Options: a. 105 kg, b. 85 kg, c. 108 kg, d. 125 kg, e. 117 kg
Example Output: b

Example Input: Problem: the average runs scored by a batsman in 30 matches is 50. in the next 15 matches the batsman scored an average of 26 runs. find his average in all the 45 matches ?
Options: a. 31, b. 42, c. 29, d. 97, e. 27
Example Output: b

Example Input: Problem: find the area of a parallelogram with base 10 cm and height 20 cm.
Options: a. 200, b. 384, c. 200, d. 244, e. 242
Example Output:
c