You will be given a definition of a task first, then some input of the task.
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.

Problem: how long does a train 110 m long travelling at 60 kmph takes to cross a bridge of 200 m in length ?
Options: a. 18.6 sec, b. 14.9 sec, c. 12.4 sec, d. 16.8 sec, e. 11.8 sec
Output:
a