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 solid yellow stripe is to be painted in the middle of a certain highway. if 1 gallon of paint covers an area of q square feet of highway, how many gallons of paint will be needed to paint a stripe of t inches wide on a stretch of highway m miles long ? ( 1 mile = 5,280 feet and 1 foot = 12 inches )
Options: ['a. ( 5,280 mt ) / 12 q', 'b. ( 5,280 pt ) / 12 m', 'c. ( 5,280 pmt ) / 12', 'd. ( 5,280 ) ( 12 m ) / pt', 'e. ( 5,280 ) ( 12 p ) / mt']

Ex Output:
a


Ex Input:
Problem: what is the tens digit of 6 ^ 10 ?
Options: a. 7, b. 3, c. 5, d. 1, e. 9

Ex Output:
a


Ex Input:
Problem: the sector of a circle has perimeter 83 cm and central angle 225 o. find its radius ?
Options: a. 21 cm, b. 15 cm, c. 14 cm, d. 24 cm, e. 28 cm

Ex Output:

c