The correct answer is A. 1.414.
The form factor of a sine wave is the ratio of its peak value to its rms value. The peak value is the maximum value of the sine wave, and the rms value is the root-mean-square value, which is a measure of the average power of the sine wave.
The form factor of a sine wave is always greater than 1, because the peak value is always greater than the rms value. The exact value of the form factor depends on the frequency of the sine wave. For a sine wave with a frequency of 1 Hz, the form factor is 1.414.
Option B is incorrect because the form factor of a sine wave is always greater than 1. Option C is incorrect because the form factor of a sine wave is always greater than 1. Option D is incorrect because the form factor of a sine wave is always greater than 1.