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 area of a parallelogram with base 10 cm and height 20 cm.
Options: a. 200, b. 384, c. 200, d. 244, e. 242

Output: c

Input: Consider Input: Problem: if x and y are positive integers and 3 + x + y + xy = 17, what is the value of x + y ?
Options: a. 3, b. 5, c. 6, d. 8, e. 9

Output: c

Input: Consider Input: Problem: a and b are 90 km apart they start to move each other simultaneously a at speed 10 and b at 5 km / hr if every hour they double their speed what is distance that a pass until he meet b ?
Options: a. 30 km, b. 40 km, c. 50 km, d. 60 km, e. 70 km
Output: d