David Lands on Planet X and Observes Objects Free-Falling with Acceleration

Multiple Choice

David lands on planet X and observes objects free-falling with acceleration 4.9 m/s^{2 s2} . If the planet is 3 times larger than the Earth, what is the planet MASS expressed in Earth masses?

A) 1/2
B) 3/2
C) 2/3
D) 9/2
E) 9/4