A band is planning a concert at a local theater. The graph below shows the ticket sales per hour. What is the slope of the line shown in the graph?

A.
-400
B.
-250
C.
-2,000
D.
-1,500

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

n

step-by-step explanation: