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: car x began traveling at an average speed of 35 miles per hour. after 72 minutes, car y began traveling at an average speed of 49 miles per hour. when both cars had traveled the same distance, both cars stopped. how many miles did car x travel from the time car y began traveling until both cars stopped ?
Options: a. 105, b. 120, c. 140, d. 147, e. 168

Output: a

Input: Consider Input: Problem: for any positive integer n, the sum of the first n positive integers equals n ( n + 1 ) / 2. what is the sum of all the integers between 100 and 200 ?
Options: a. 4545, b. 5050, c. 6525, d. 4352, e. 4652

Output: b

Input: Consider Input: Problem: in a garden, there are 10 rows and 12 columns of mango trees. the distance between the two trees is 2 m and a distance of one meter is left from all sides of the boundary of the length of the garden is :
Options: a. 450 sq mtrs, b. 460 sq mtrs, c. 480 sq mtrs, d. 490 sq mtrs, e. 470 sq mtrs
Output: c