To find the surface area \( A \) of a sphere, you can use the formula:
\[ A = 4\pi r^2 \]
where \( r \) is the radius of the sphere. The radius is half of the diameter. Given that the diameter of the sphere is 30 inches, the radius \( r \) would be:
\[ r = \frac{30}{2} = 15 \text{ inches} \]
Now, substitute the radius into the surface area formula:
\[ A = 4\pi (15)^2 \]
Calculating \( (15)^2 \):
\[ (15)^2 = 225 \]
Now, substitute back into the surface area formula:
\[ A = 4\pi \times 225 \] \[ A = 900\pi \]
Thus, the surface area of the sphere is:
\[ 900\pi \text{ in}^2 \]
The correct response is 900π in.².