Determine the concavity of the graph of $f(x) = -5 - x^2$ between $x= -5$ and $x= 1$ by calculating average rates of change over intervals of length 2.

a) The average rate of change over the interval $-5 \leq x \leq -3 =$

b) The average rate of change over the interval $-3 \leq x \leq -1 =$

c) The average rate of change over the interval $-1 \leq x \leq 1 =$

d) Based your answers for the rates of change, the graph of the function $f(x)$ is
A. Concave Up
B. Concave Down
C. Both concave up and concave down