Given the task definition and input, reply with output. 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: a man performs 3 / 5 of the total journey by rail, 17 / 20 by bus and the remaining 6.5 km on foot. his total journey is
Options: a. 65 km, b. 100 km, c. 120 km, d. 130 km, e. 140 km
d