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: points a, b, c, and d, in that order, lie on a line. if ab = 3 cm, ac = 4 cm, and bd = 8 cm, what is cd, in centimeters ?
Options: a. 7, b. 2, c. 3, d. 4, e. 5
Example Output: a

Example Input: Problem: the total age of a and b is 12 year more than the total age of b and c. c is how many years younger than a ?
Options: a. 12, b. 24, c. data inadequate, d. none of these, e. 34
Example Output: a

Example Input: Problem: on a certain road 10 % of the motorists exceed the posted speed limit and receive speeding tickets, but 24 % of the motorists who exceed the posted speed limit do not receive speeding tickets. what percent of the motorists on the road exceed the posted speed limit ?
Options: a. 10.5 %, b. 13.2 %, c. 15 %, d. 22 %, e. 30 %
Example Output:
b