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: what is the total number of integers between 10 and 50 that are divisible by 2 ?
Options: a. 18, b. 19, c. 22, d. 25, e. 10

Ex Output:
b

Ex Input:
Problem: at joes steakhouse the hourly wage for a chef is 20 % greater than that of a dishwasher, and the hourly wage of a dishwasher is half as much as the hourly wage of a manager. if a managers wage is $ 6.50 per hour, how much less than a manager does a chef earn each hour ?
Options: a. $ 2.6, b. $ 2.40, c. $ 3.40, d. $ 4.40, e. $ 5.40

Ex Output:
a

Ex Input:
Problem: average monthly income of a family of 4 earning members was rs. 840. one of the earning members died and therefore, the average income came down to rs 650. the income of the deceased was ?
Options: a. rs. 692.80, b. rs. 820, c. rs. 990, d. rs. 1410, e. none

Ex Output:
d