Decide If the Function Is an Exponential Function $$y = - 8 \cdot 4 ^ { x }$$

Multiple Choice

Decide if the function is an exponential function. If it is, state the initial value and the base.
- $$y = - 8 \cdot 4 ^ { x }$$

A) Exponential Function; base $= 4$ ; initial value $= - 8$
B) Not an exponential function
C) Exponential Function; base $= x$ ; initial value $= - 8$
D) Exponential Function; base $= - 32$ ; initial value $= 1$