The North American Plate and the Pacific Plate Are Sliding

The North American plate and the Pacific plate are sliding past one another at a rate of approximately 3 cm/year. San Francisco, which is located on the edge of the North American plate, is sliding southward toward Los Angles, which is located on the Pacific Plate. If they are currently separated by a distance of 600 km, how many years will it take for the two cities to meet?

A) 3 million years
B) 300,000 years
C) 20 million years
D) 20,000 years
E) 600 years