Teacher: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.
Teacher: Now, understand the problem? Solve this instance: Problem: a train 360 m long is running at a speed of 45 km / hr. in what time will be pass a bridge 140 m long ?
Options: a. 40 sec, b. 42 sec, c. 45 sec, d. 48 sec, e. none
Student:
a