In Another Solar System, a Planet Has an Airless Moon $4.0 \times 10 ^ { 5 }$

Multiple Choice

In another solar system, a planet has an airless moon Zygo that is $4.0 \times 10 ^ { 5 }$ m in diameter. Experiments reveal that a freely falling object at the surface of Zygo accelerates at $0.20 \mathrm {~m} / \mathrm { s } ^ { 2 }$ What is the mass of Zygo? $\left( G = 6.67 \times 10 ^ { - 11 } \mathrm {~N} \cdot \mathrm { m } ^ { 2 } / \mathrm { kg } ^ { 2 } \right)$

A) $4.8 \times 10^{20} \mathrm {~kg}$
B) $4.8 \times 10 ^ { 19 } \mathrm {~kg}$
C) $1.2 \times 10^{20} \mathrm {~kg}$
D) $2.4 \times 10^{20} \mathrm {~kg}$
E) $2.4 \times 10 ^ { 19 } \mathrm {~kg}$