Use the exponent property regarding a power to power. When you have a power to power, you multiply both powers. In this case, you will get 7^-6. That is equivalent to the first option. I hope this helped, though it is a bit late xD.
First, we must solve for the radius of the sphere:
V=



r=(3

)

r=(3*

)

r≈5.99
Second, we must solve for surface area:
A=4


A=4*

*

A≈450.88
D=r^2 means diameter equals radius squared
This doesn't make any sense