Answer:
"circle; diameter of 9; center at (-4.5,0)"
Explanation:
The polar equation of a circle centered on an axis, would take the forms:
1. Positive x-axis
r = (diameter) Cos θ
2. Positive y-axis
r = (diameter) Sin θ
3. Negative x-axis
r = - (diameter) Cos θ
4. Negative y-axis
r = - (diameter) Sin θ
As we see from the equation given, the diameter is 9 and it is centered n negative x-axis. And the center is Diameter divided by 2. So negative x axis has the center at (-9/2, 0) = (-4.5, 0)
The first choice is correct.