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: find the value o f 72519 x 9999 = m ?
Options: a. 434539873, b. 355797990, c. 435453490, d. m = 725117481, e. 873430134

Ex Output:
d


Ex Input:
Problem: a 11 % stock yields 8 %. the market value of the stock is :
Options: a. rs. 72, b. rs. 137.50, c. rs. 112.50, d. rs. 116.50, e. none of these

Ex Output:
b


Ex Input:
Problem: a train is 485 meter long is running at a speed of 45 km / hour. in what time will it pass a bridge of 140 meter length
Options: a. 20 seconds, b. 30 seconds, c. 40 seconds, d. 50 seconds, e. none of these

Ex Output:

d