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: the dimensions of a room are 25 feet * 15 feet * 12 feet. what is the cost of white washing the four walls of the room at rs. 7 per square feet if there is one door of dimensions 6 feet * 3 feet and three windows of dimensions 4 feet * 3 feet each ?
Options: a. s. 4538, b. s. 6342, c. s. 4518, d. s. 4530, e. s. 4517

Ex Output:
b


Ex Input:
Problem: car z travels 50 miles per gallon of gasoline when driven at a constant rate of 45 miles per hour, but travels 20 percent fewer miles per gallon of gasoline when driven at a constant rate of 60 miles per hour. how many miles does car z travel on 10 gallons of gasoline when driven at a constant rate of 60 miles per hour ?
Options: a. 320, b. 375.2, c. 400, d. 408.3, e. 440

Ex Output:
c


Ex Input:
Problem: audrey 4 hours to complete a certain job. ferris can do the same job in 3 hours. audrey and ferris decided to collaborate on the job, working at their respective rates. while audrey worked continuously, ferris took 5 breaks of equal length. if the two completed the job together in 2 hours, how many minutes long was each of ferris ’ breaks ?
Options: a. 5, b. 6, c. 15, d. 20, e. 25

Ex Output:

b