C. 51* I am pretty sure is it
Y = a(b^x)
y=mx + b is the equation of a line. It is a linear function because it has a constant rate of change.
y = a(b^x) is an exponential function because it has has an exponent and its rate of change is not constant
Answer:

Step-by-step explanation:
'x = -3', when graphed, passes through the point (-3,7) and (-3,0).
Since the line passes (-3,0), the x-intercept is -3.
(-3, 7) lies on the equation.
I have attached a picture of the graphed equation.
'x = -3' should be the correct answer.