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: in a mayoral election, candidate x received 1 / 2 more votes than candidate y, and candidate y received 2 / 5 fewer votes than z. if z received 25000 votes how many votes did candidate x received ?
Options: a. 18000, b. 22500, c. 24000, d. 26000, e. 32000
Example Output: b

Example Input: Problem: if a man lost 8 % by selling oranges at the rate of 25 a rupee at how many a rupee must he sell them to gain 25 % ?
Options: a. 20, b. 15, c. 18.4, d. 20, e. 12.8
Example Output: c

Example Input: Problem: a motorcyclist goes from bombay to pune, a distance of 256 kms at an average of 32 kmph speed. another man starts from bombay by car 2 ½ hours after the first, and reaches pune ½ hour earlier. what is the ratio of the speed of the motorcycle and the car ?
Options: a. 1: 2, b. 1: 5, c. 1: 4, d. 1: 1, e. 5: 8
Example Output:
e