Both a Mass-Spring System and a Simple Pendulum Have a Period

Multiple Choice

Both a mass-spring system and a simple pendulum have a period of 1 s.Both are taken to the moon in a lunar landing module.While they are inside the module on the surface of the moon,

A) the pendulum has a period longer than 1 s.
B) the mass-spring system has a period longer than 1 s.
C) both a and b are true.
D) the periods of both are unchanged.
E) one of them has a period shorter than 1 s.