the time required for one cycle, a complete motion that returns to its starting point, it called the medium frequency period periodic motion

The correct answer to the following question will be "Period".

Explanation:

The Period seems to be the time deemed necessary for such a perfect cycle of vibration to transfer a particular moment. Because as the amplitude of the wave raises, the wavelength falls.

It is denoted by "T" and its formula will be:

⇒  

Where, T = Period

            F = Frequency

The other given choices are not related to the given circumstances. So that the above would be the right answer.