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.

Input: Consider Input: Problem: find the value of 1 / ( 3 + 1 / ( 3 + 1 / ( 3 - 1 / 3 ) ) )
Options: a. 21 / 29, b. 27 / 89, c. 89 / 21, d. 29 / 21, e. none

Output: b


Input: Consider 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']

Output: a


Input: Consider Input: Problem: a couple spent $ 198 in total while dining out and paid this amount using a credit card. the $ 198 figure included a 20 percent tip which was paid on top of the price which already included a sales tax of 10 percent on top of the price of the food. what was the actual price of the food before tax and tip ?
Options: a. $ 130, b. $ 140, c. $ 150, d. $ 160, e. $ 170


Output: c