A Simple Pendulum of Length 2

Multiple Choice

A simple pendulum of length 2.00 m is used to measure the acceleration of gravity at the surface of a distant planet. If the period of such a pendulum is 7.00 s, what is the acceleration of gravity?

A) 7.89 m/s²
B) 6.78 m/s²
C) 1.61 m/s²
D) 0.513 m/s²
E) 17.8 m/s²