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: a shop owner professes to sell his articles at certain cost price but he uses false weights with which he cheats by 12 % while buying and by 30 % while selling. what is his percentage profit ?
Options: a. 10.22 %, b. 20.22 %, c. 21.22 %, d. 60 %, e. ca n ' t be calculated

Ex Output:
d


Ex Input:
Problem: if a / b = 4 / 3, then ( 3 a + 2 b. / ( 3 a - 2 b. = ?
Options: a. 6, b. 3, c. 5, d. - 1, e. none

Ex Output:
b


Ex Input:
Problem: two equally sized jugs full of water are each emptied into two separate unequally sized empty jugs, x and y. now, jug x is 1 / 5 full, while jug y is 4 / 7 full. if water is poured from jug x into jug y until jug y is filled, what fraction of jug x then contains water ?
Options: a. 0, b. 1 / 15, c. 2 / 15, d. 1 / 20, e. 2 / 10

Ex Output:

d