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: john left home and drove at the rate of 45 mph for 2 hours. he stopped for lunch then drove for another 3 hours at the rate of 45 mph to reach his destination. how many miles did john drive ?
Options: a. 235 miles., b. 245 miles., c. 225 miles., d. 265 miles., e. 275 miles.
c

Problem: how much is 60 % of 40 is greater than 4 / 5 of 30 ?
Options: a. 8, b. 3, c. 7, d. 0, e. 1
d

Problem: a man sitting in a train which is travelling at 100 kmph observes that a goods train, travelling in opposite direction, takes 9 seconds to pass him. if the goods train is 280 m long, find its speed ?
Options: a. 52 kmph., b. 62 kmph., c. 12 kmph., d. 80 kmph., e. none

c