During what interval was the bicyclist's speed the greatest?

a. the first hour to the second hour
b. the second hour to the fourth hour
c. the fourth hour to the sixth hour
d. the sixth hour to the eighth hour

You have to look at the y-axis (or subtract the y numbers ex 34-12=22 which is how we know A is going up by 22 per hour)
A is going up by 22 every 1 hour.
B is going up by 36/2=18 every 1 hour.
C is going up by 34/2=17 every 1 hour.
D is going up by 32/2=16 every 1 hour.
The answer is A. It's traveling the most distance in miles per hour.