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: how many multiples of 4 are there between 12 and 104, inclusive ?
Options: a. 21, b. 22, c. 23, d. 24, e. 25

Ex Output:
d


Ex Input:
Problem: the average weight of 6 person ' s increases by 4.5 kg when a new person comes in place of one of them weighing 75 kg. what might be the weight of the new person ?
Options: a. 160 kg, b. 175 kg, c. 180 kg, d. 102 kg, e. 190 kg

Ex Output:
d


Ex Input:
Problem: a producer of tea blends two varieties of tea from two tea gardens one costing rs 18 per kg and another rs 20 per kg in the ratio 5: 3. if he sells the blended variety at rs 21 per kg, then his gain percent is
Options: a. 12 %, b. 13 %, c. 14 %, d. 15 %, e. 16 %

Ex Output:

a