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.

Example Input: Problem: if the sum of 5 consecutive even positive integers is a, then the sum of the next 5 even consecutive integers in terms of a is :
Options: a. a + 5, b. a + 10, c. a + 25, d. a + 50, e. 2 a + 5
Example Output: d

Example Input: Problem: for the past n days, the average ( arithmetic mean ) daily production at a company was 50 units. if today ' s production of 110 units raises the average to 55 units per day, what is the value of n ?
Options: a. 9, b. 11, c. 13, d. 15, e. 17
Example Output: b

Example Input: Problem: in what time will a railway train 40 m long moving at the rate of 36 kmph pass a telegraph post on its way ?
Options: a. 3 sec, b. 4 sec, c. 5 sec, d. 6 sec, e. 7 sec
Example Output:
b