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: the product of two positive integers is 675 and their difference is 2. what is the bigger number ?
Options: a. 21, b. 23, c. 25, d. 27, e. 29

Ex Output:
d


Ex Input:
Problem: a man ' s speed with the current is 18 km / hr and the speed of the current is 2.5 km / hr. the man ' s speed against the current is ?
Options: a. 10, b. 18, c. 50, d. 30, e. 40

Ex Output:
b


Ex Input:
Problem: 70 % of x is greater than 1 / 3 rd of x by 110. what is x ?
Options: a. 100, b. 200, c. 300, d. 350, e. 400

Ex Output:

c