Someone plz help

The planet Mars has two moons - Phobos and Deimos. Phobos has a mass of 10.8×10^15. Kilograms, and Deimos has a mass of 2.0×10^15 kilograms. How much greater is the mass of Phobos than the mass of Deimos? A)8.8x10^15 kilograms
B) 8.8x 10^16 kilograms
C)9.2x 10^14 kilograms
D)9.2x10^15 kilograms