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.

Example Input: Problem: a couple spent $ 211.20 in total while dining out and paid this amount using a credit card. the $ 211.20 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. $ 120, b. $ 140, c. $ 150, d. $ 160, e. $ 180
Example Output: d

Example Input: Problem: together, 15 type a machines and 7 type b machines can complete a certain job in 4 hours. together 8 type b machines and 15 type c machines can complete the same job in 11 hours. how many q hours would it take one type a machine, one type b machine, and one type c machine working together to complete the job ( assuming constant rates for each machine. ?
Options: a. 22 hours, b. 30 hours, c. 44 hours, d. 60 hours, e. it can not be determined from the information above.
Example Output: c

Example Input: Problem: the average height of 35 boys in a class was calculated as 185 cm. it has later found that the height of one of the boys in the class was wrongly written as 166 cm whereas his actual height was 106 cm. find the actual average height of the boys in the class ( round off your answer to two decimal places ). ?
Options: a. 178.27 cm, b. 183.29 cm, c. 978.29 cm, d. 178.89 cm, e. 176.29 cm
Example Output:
b