a$.$ Show the relationship between doctors and physical exams given with three curves, where the number of doctors is on the horizontal axis and the number of examinations is on the vertical axis.

b$.$ Describe how the three relationships compare with one another.

c$.$ Is a change in the number of doctors a shift of or a movement along the curve?

d$.$ Is a change in the size of the clinic a shift of or a movement along the curve?