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: evaluate: 98612 / 22 * 11 * 70 = ?
Options: a. 700.4, b. 704.4, c. 740.4, d. 744.4, e. 700.0
Example Output: b

Example Input: Problem: the population of a town increases 25 % and 40 % respectively in two consecutive years. after the growth the present population of the town is 1750. then what is the population of the town 2 years ago ?
Options: a. a. 750, b. b. 800, c. c. 850, d. d. 900, e. e. 950
Example Output: b

Example Input: Problem: the average weight of a, b and c is 45 kg. if the average weight of a and b be 40 kg and that of b and c be 47 kg, then the weight of b is :
Options: a. 39 kg, b. 32 kg, c. 33 kg, d. 34 kg, e. none of these
Example Output:
a