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.

Input: Consider Input: Problem: the average of runs of a cricket player of 20 innings was 32. how many runs must he make in his next innings so as to increase his average of runs by 8 ?
Options: a. 96, b. 200, c. 128, d. 116, e. 122

Output: b

Input: Consider Input: Problem: buses a and b start from a common bus stop x. bus a begins to travel in a straight line away from bus b at a constant rate of 20 miles per hour. one hour later, bus b begins to travel in a straight line in the exact opposite direction at a constant rate of 80 miles per hour. if both buses travel indefinitely, what is the positive difference, in minutes, between the amount of time it takes bus b to cover the exact distance that bus a has covered and the amount of time it takes bus b to cover twice the distance that bus a has covered ?
Options: a. 36, b. 72, c. 132, d. 144, e. 180

Output: c

Input: Consider Input: Problem: two bike riders ride in opposite directions around a circular track, starting at the same time from the same point. biker a rides at a speed of 16 kmph and biker b rides at a speed of 14 kmph. if the track has a diameter of 40 km, after how much time ( in hours ) will the two bikers meet ?
Options: a. 8.18 hrs., b. 6.18 hrs., c. 4.18 hrs., d. 1.18 hrs., e. 7.18 hrs.
Output: c