To Study Traffic Flow Along a Major Road, the City

Multiple Choice

To study traffic flow along a major road, the city installs a device at the edge of the road at 1:00a.m.The device counts the cars driving past, and records the total periodically.The resulting data is plotted on a graph, with time (in hours since installation) on the horizontal axis and the number of cars on the vertical axis.The graph is shown below; it is the graph of the function C(t) = Total number of cars that have passed by after t hours.When is the traffic flow greatest?

A) 2:00 am
B) 3:00 am
C) 4:00 am
D) 5:00 am