Detailed Instructions: You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
Q: Question: The Cottage Grove Loop Line travels the distance between the north side and the south side of the city in two hours, at a rate of speed of 100 km/h. How long is a round trip, measured in kilometers?

Option A: 100 km

Option B: 150 km

Option C: 200 km

Option D: 300 km

Option E: 400 km
A:
Option E