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.

[Q]: Problem: two trains travel in opposite directions at 36 kmph and 45 kmph and a man sitting in slower train passes the faster train in 8 seconds. the length of the faster train is
Options: a. 80 m, b. 100 m, c. 120 m, d. 180 m, e. 160 m
[A]: b

[Q]: Problem: the average of 11 10 prime numbers which are odd is ?
Options: a. 17.72, b. 18.52, c. 19.63, d. 16.53, e. 15.63
[A]: a

[Q]: Problem: evaluate: | 5 - 8 ( 3 - 12 ) | - | 5 - 11 | = ?
Options: a. 40, b. 50, c. 60, d. 71, e. 80
[A]:
d