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: what percent is 6 gm of 1 kg ?
Options: a. 1.5 %, b. 0.5 %, c. 0.6 %, d. 3.5 %, e. 4 %
Example Output: c

Example Input: Problem: 1 men takes 37 $ to eat a pizza in restaurant such that it have discount multiple of 4 if u eat more pizza. discount increase by multiple of 4 every pizza u eat. for 1 pizza 0 % off. for 2 pizza % off for 3 pizza 8 % off. pizza without discount is 10 $. how much that man eats the pizza.
Options: a. 2, b. 3, c. 4, d. 5, e. 6
Example Output: b

Example Input: Problem: find the area of trapezium whose parallel sides are 20 cm and 18 cm long, and the distance between them is 14 cm.
Options: a. 335 cm 2, b. 885 cm 2, c. 285 cm 2, d. 825 cm 2, e. 266 cm 2
Example Output:
e