which of the following changes will increase the frequency of an oscillating pendulum?

Question

a. an increase in the mass of the pendulum.
b. an increase in the initial height of release.
c. an increase in the length of the rope.
d. more than one of the above
e. none of the above
explain your answer
I chose c. How do I explain my answer.

Answer 1

it will be hard, since it is wrong.
do some reading on pendulums and their periods

Answer 2

does not depend on mass
does not depend much on initial release height, but second order higher would be lower, not higher frequency
frequency goes DOWN (period up) with longer rope

so in the end e

Answer 3

So it's e because a pendulum can increase frequency if it had a stronger gravity field or by shortening the rope of the pendulum itself.