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.

Ex Input:
Problem: a car is 15 minutes late by running at a speed of 4 / 5 th of its actual speed. the actual time taken by the car to cover that distance is :
Options: a. 30 minutes, b. 1 hour, c. 2 hours, d. 3 hours, e. none of these

Ex Output:
b


Ex Input:
Problem: a and b go around a circular track of length 200 m on a cycle at speeds of 36 kmph and 72 kmph. after how much time will they meet for the first time at the starting point ?
Options: a. 120 sec, b. 198 sec, c. 178 sec, d. 20 sec, e. 276 sec

Ex Output:
d


Ex Input:
Problem: convert 2.3 hectares in ares
Options: a. 130 ares., b. 160 ares., c. 180 ares., d. 230 ares., e. 250 ares.

Ex Output:

d