The correct answer is: 1 second.
The frequency of a wave is the number of waves that pass a given point in a given amount of time. It is measured in hertz (Hz), which is equal to one wave per second. The period of a wave is the amount of time it takes for one wave to complete its cycle. It is measured in seconds.
In this case, the period of the sine wave is 1 second. This means that it takes 1 second for the wave to complete one cycle. The frequency of the wave is therefore 1/1 = 1 Hz.
Option A is incorrect because the frequency of a wave cannot be greater than its period.
Option B is incorrect because the frequency of a wave cannot be equal to its period.
Option C is incorrect because the frequency of a wave cannot be less than its period.
Option D is incorrect because the frequency of a wave cannot be equal to 0 Hz.