Answer:
F. 20
Step-by-step explanation:
The constant rate of change for the graph can be calculate as the division of the number of students by the number of buses.
So, if the lines passes by a point (1, 20), 1 is the number of buses and 20 is the number of students. Then, the constant rate of change is:
20/1 = 20
So, the answer is:
F. 20