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: vehicle x is 22 miles ahead of vehicle y, which is traveling the same direction along the same route as vehicle x. if vehicle x is traveling at an average speed of 36 miles per hour and vehicle y is traveling at an average speed of 45 miles per hour, how long will it take vehicle y to overtake and drive 23 miles ahead of vehicle x ?
Options: a. 5 hours, b. 7 hours 20 minutes, c. 4 hours, d. 3 hours 45 minutes, e. 2 hours 30 minutes

Output: a


Input: Consider Input: Problem: a and b together can complete work in 6 days. a alone starts working and leaves it after working for 4 days completing only half of the work. in how many days it can be completed if the remaining job is undertaken by b ?
Options: a. 4, b. 12, c. 5, d. 6, e. 7

Output: b


Input: Consider Input: Problem: if # is an operation which results in adding the digits of integer until a single digit is left, what is the probability that a number picked up in first 90 positive integers will have the result of # as an odd digit ? ( example 99 = 9 + 9 = 18 = 1 + 8 = 9, so # = 9 )
Options: a. 4 / 10, b. 4 / 9, c. 1 / 2, d. 6 / 10, e. 5 / 9


Output: e