Final answer:
The frequency of the nasal murmur is around 300 Hz, which is within the human audible range of 20 Hz to 20,000 Hz.
Step-by-step explanation:
The nasal murmur is a characteristic resonance peak experienced when producing nasal sounds. The frequency of the nasal murmur typically occurs around 250 Hz to 300 Hz.
Therefore, the correct answer to the question about the frequency of the nasal murmur is (a) 300 Hz.
Humans are capable of hearing sounds in the range of roughly 20 Hz to 20,000 Hz,
which includes the nasal murmur frequency. This frequency is well within the audible range for humans, which is important for speech perception and linguistics.