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: an 80 - liter solution of cool - drink is made from 10 % jasmine water. if 5 liters of jasmine and 15 liters of water were added to the solution, what percent of the solution is jasmine ?
Options: a. 11 %, b. 13 %, c. 15 %, d. 17 %, e. 19 %

Ex Output:
b

Ex Input:
Problem: what is the least number of squares tiles required to pave the floor of a room 15.17 m long and 9.02 m broad ?
Options: ['a. 814', 'b. 266', 'c. 287', 'd. 999', 'e. 661']

Ex Output:
a

Ex Input:
Problem: a women purchased 3 towels @ rs. 100 each, 5 towels @ rs. 150 each and two towels at a certain rate which is now slipped off from his memory. but she remembers that the average price of the towels was rs. 165. find the unknown rate of two towels ?
Options: a. a. 400, b. b. 450, c. c. 500, d. d. 550, e. e. 600

Ex Output:
e