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: john left home and drove at the rate of 45 mph for 2 hours. he stopped for lunch then drove for another 3 hours at the rate of 45 mph to reach his destination. how many miles did john drive ?
Options: a. 235 miles., b. 245 miles., c. 225 miles., d. 265 miles., e. 275 miles.

Ex Output:
c


Ex Input:
Problem: at the wholesale store you can buy an 8 - pack of hot dogs for $ 1.55, a 20 - pack for $ 3.05, and a 250 - pack for $ 22.95. what is the greatest number of hot dogs you can buy at this store with $ 205 ?
Options: a. 1,108, b. 2,100, c. 2,140, d. 2,124, e. 2,256

Ex Output:
c


Ex Input:
Problem: cost is expressed by the formula tb ^ 4. if b is doubled, the new cost w is what percent of the original cost ?
Options: a. w = 200, b. w = 600, c. w = 800, d. w = 1600, e. w = 50

Ex Output:

d