Answer: Amplitude
If we are talking about simple harmonic motion, we are talking about waves and in this case the frequency
is related to the period of oscillation
in an inverse proportion.
Now, for a mass-on-a-spring system the period is given by:
![T=2\pi\sqrt{(m)/(k)}](https://img.qammunity.org/2020/formulas/physics/high-school/ni5l3u4lr657au9aogz0k0mrcfc1ee6g1i.png)
Where
is the oscillating mass and
the spring constant, which depends on the spring stillness.
As we can see in this equation:
If we change
and
we will affect the period, hence the frequency.
Nevertheless, we do not see any relation with the Amplitude, this means the period (hence the frequency) does not depend on the amplitude.