Final answer:
Long waves with low frequency have a low pitch. The pitch of a sound is directly related to the frequency, with higher frequencies corresponding to higher pitches and lower frequencies to lower pitches.
Step-by-step explanation:
The question regarding the pitch of long waves with low frequency can be answered by understanding the relationship between frequency and pitch. Long waves have a low frequency, and low frequency sounds are perceived by our ears as having a low pitch. Therefore, the correct answer to the multiple choice question is 'a. Low pitch'.
In the context of sound waves, pitch is a sensory characteristic of sound that allows us to differentiate between high and low sounds. Hair cells located near the base of the basilar membrane, for example, respond best to high-frequency sounds, which have a higher pitch. Conversely, cells located near the apex of the membrane respond best to low-frequency sounds, which have a low pitch. As an example, the roar of a lion has a low pitch, while the chirp of a bird is of a high pitch.