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.

Ex 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

Ex Output:
a


Ex Input:
Problem: a rectangular tiled patio is composed of 96 square tiles. the rectangular patio will be rearranged so that there will be 2 fewer columns of tiles and 4 more rows of tiles. after the change in layout, the patio will still have 96 tiles, and it will still be rectangular. how many rows are in the tile patio before the change in layout ?
Options: a. 5, b. 6, c. 8, d. 13, e. 28

Ex Output:
c


Ex Input:
Problem: the h. c. f of two numbers is 23 and the other two factors of their l. c. m are 13 and 14. the larger of the two numbers is :
Options: a. 338, b. 278, c. 322, d. 231, e. 121

Ex Output:

c


