Haploid cells! Hope this helps :)
Do you want the answer or know how to get the answer?
The answer to this question would be frequency.
The pitch of a sound makes is directly related to the frequency of the vibration. For every octave, the number of frequency will be increased 2 times. The frequency is influenced by various things. Changing the length of the instrument is the easiest method to change the frequency.
The answer is d) it encloses specific structures
