The Graph Shows the Total Sales in Thousand of Dollars $\frac{4}{3}$

Multiple Choice

The graph shows the total sales in thousand of dollars from the distribution of x thousand catalogs. Find the average rate of change of sales with respect to the number of catalogs distributed for the change in x.

-30 to 40

A) $\frac{4}{3}$
B) 0
C) 1
D) $\frac{3}{4}$