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: if an investor puts $ 800 in a savings account that earns 10 percent annual interest compounded semiannually, how much money will be in the account after one year ?
Options: a. $ 878, b. $ 880, c. $ 882, d. $ 884, e. $ 886

Ex Output:
c


Ex Input:
Problem: a worker is paid a regular rate of rs. 30 for completing a survey. the worker completes 100 surveys per week. for any survey involving the use of her cellphone, she is paid at a rate of that is 20 % higher than her regular rate. if she completed 50 surveys involving the use of her cellphone, how much did she get that week ?
Options: a. 2200, b. 1100, c. 2500, d. 2800, e. 3300

Ex Output:
e


Ex Input:
Problem: two kinds of vodka are mixed in the ratio 1: 2 and 2: 1 and they are sold fetching the profit 10 % and 30 % respectively. if the vodkas are mixed in equal ratio and the individual profit percent on them are increased by 4 / 3 and 5 / 3 times respectively, then the mixture will fetch the profit of
Options: a. 18 %, b. 20 %, c. 30 %, d. 23 %, e. can not be determined

Ex Output:

c