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: | - 2 | ( | - 25 | - | 5 | ) = ? ? source: preparation material mba center
Options: a. 40, b. – 60, c. 60, d. 75, e. 100
Example Output: a

Example Input: Problem: excluding the stoppages, the speed of a bus is 48 km / hr and including the stoppages the speed of the bus is 12 km / hr. for how many minutes does the bus stop per hour ?
Options: a. 45 min, b. 10 min, c. 12 min, d. 20 min, e. 18 min
Example Output: a

Example Input: Problem: mr. loyd wants to fence his square shaped land of 120 sqft each side. if a pole is laid every 10 ft how many poles do he need ?
Options: a. 20, b. 30, c. 48, d. 50, e. 60
Example Output:
c