On a Given Day, the Flow Rate F (Cars Per

Multiple Choice

On a given day, the flow rate F (cars per hour) on a congested roadway is given by , where v is the speed of the traffic in miles per hour. What speed will maximize the flow rate on the road? Round your answer to the nearest mile per hour. ​

A) 20 miles per hour
B) 18 miles per hour
C) 19 miles per hour
D) 11 miles per hour
E) 21 miles per hour