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: in a certain pond, 50 fish were caught, tagged, and returned to the pond. a few days later, 50 fish were caught again, of which 5 were found to have been tagged. if the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond, what is the approximate number of fish in the pond ?
Options: a. 400, b. 500, c. 1,250, d. 2,500, e. 10,000

Ex Output:
b


Ex Input:
Problem: 50 % of a number is more than 40 % of 120 by 180. find the number ?
Options: a. 456, b. 480, c. 420, d. 445, e. 320

Ex Output:
a


Ex Input:
Problem: for a certain art exhibit, a museum sold admission tickets to a group of 50 people every 5 minutes from 9: 00 in the morning to 5: 55 in the afternoon, inclusive. the price of a regular admission ticket was $ 10 and the price of a student ticket was $ 6. if on one day 3 times as many regular admission tickets were sold as student tickets, what was the total revenue from ticket sales that day ?
Options: a. $ 24960, b. $ 25920, c. $ 28080, d. $ 38500, e. $ 48600

Ex Output:

e