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 l. c. m of two numbers is 495 and their h. c. f is 5. if the sum of the numbers is 100, then their difference is
Options: a. 19, b. 10, c. 28, d. 27, e. 29

Ex Output:
b


Ex Input:
Problem: raman mixed 48 kg of butter at rs. 150 per kg with 36 kg butter at the rate of rs. 125 per kg. at what price per kg should he sell the mixture to make a profit of 40 % in the transaction ?
Options: a. 129, b. 287, c. 195, d. 188, e. 112

Ex Output:
c


Ex Input:
Problem: there are 5 boxes in a cargo. the weight of the 1 st box is 200 kg, the weight of the 2 nd box is 20 % higher than the third box, whose weight is 25 % higher than the 1 st box weight. the 4 th box which weighs 350 kg is 30 % lighter than the 5 th box. find the difference in average weight of the 4 heaviest boxes and the 4 lightest boxes.
Options: a. 22, b. 75, c. 25, d. 70, e. 11

Ex Output:

b