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: a train 510 m long is running at a speed of 45 km / hr. in what time will it pass a bridge 140 m long ?
Options: a. 40, b. 52, c. 26, d. 21, e. 14

Output: b

Input: Consider Input: Problem: ms. harris invested in fund x and fund b. the total amount she invested, in both funds combined, was $ 100000. in one year, fund x paid 23 % and fund b paid 17 %. the interest earned in fund b was exactly $ 200 greater than the interest earned in fund x. how much did ms. morris invest in fund x ?
Options: a. $ 32000, b. $ 36000, c. $ 40000, d. $ 42000, e. $ 45,000

Output: d

Input: Consider Input: Problem: the average temperature for monday, tuesday, wednesday and thursday was 48 degrees and for tuesday, wednesday, thursday and friday was 46 degrees. if the temperature on monday was 42 degrees. find the temperature on friday ?
Options: a. 34, b. 55, c. 66, d. 81, e. 21
Output: a