Now, assume that isabella’s savings institution modifies the terms of her account and agrees to pay 6.6% in compound interest on her $1,400 balance. all other things being equal, how much money will isabella have in her account in 13 years?

Earth is spherical which has the volume (V) equal to,
                                   V = 4πr³ / 3
its surface area (SA) is equal to 
                                   SA = 4πr²
The ratio of the surface area to volume is therefore equal to 3/r. This is equal to 3/3,960 which is simplified as 0.00076. The answer is letter B.