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.

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']
a

Problem: jack has two dice, one has 6 equally probable sides, labeled 1, 2, 3, 4, 5, 6, and the other has 7 equally probable sides, labeled 1, 2, 3, 4, 5, 6, 7. if jack rolls both dice what is the probability that both of the number ' s sum will be 13 ?
Options: a. 3 / 14, b. 2 / 7, c. 1 / 3, d. 1 / 42, e. 12 / 21
d

Problem: a box contains 21 electric bulbs, out of which 4 are defective. two bulbs are chosen at random from this box. the probability that at least one of these is defective is
Options: a. 4 / 19, b. 7 / 19, c. 12 / 19, d. 21 / 95, e. 31 / 88

e