The rate of a traveling object varies directly with distance and inversely with time. This relation applies to the Johnsons, as they are traveling by car on their way to a vacation spot 240 miles from their home. They plan to travel at the speed limit of 60 mph. How much time will it take them to travel there, and how much time could they save by going 80 mph?

A. 1 hour; 4 hours
B. 4 hours; 2 hours
C. 3 hours; 1 hour
D. 4 hours; 1 hour