Which harmonic occurs an octave above the fundamental frequency?

The first harmonic, also known as the fundamental frequency, is the lowest frequency produced by a vibrating object, such as a string or an air column. It sets the basic pitch that one perceives. The harmonics of a wave are integer multiples of this fundamental frequency. When we refer to the harmonic that occurs an octave above the fundamental frequency, we are indicating the second harmonic.

To clarify, the second harmonic has a frequency that is twice that of the fundamental, which means it corresponds to a musical interval of an octave above the first harmonic. Therefore, while the question asks specifically about the harmonic that occurs an octave above the fundamental frequency, the first harmonic itself is considered the fundamental pitch and does not serve that role.

Consequently, in the context of this question, the answer is indeed the second harmonic that fits the description of being an octave above the fundamental. The first harmonic is the fundamental frequency itself.