The difference between musical sound and noise is due to: 

Answer is C.

Pitch is that characteristic of a musical sound by which a shrill sound can be distinguished from a grave one, even though the two sounds may be of the same intensity. It is also defined as that characteristic of sound by which the ear assigns it a place on a musical scale. When a stretched string is plucked, a sound of a certain pitch sensation is produced. If the tension in the string is increased, the pitch (the shrillness) becomes higher. Increasing the tension, also increases the frequency of vibration. Therefore, pitch is intimately related to frequency. But frequency alone does not determine the pitch. Below 1000Hz, the pitch is slightly higher than the frequency and above 1000Hz the position is reversed. The loudness of sound also affects the pitch up to 1000Hz. An increase in loudness causes a decrease in pitch. From about 1000 to 3000Hz, the pitch is independent of loudness, while above 3000Hz an increase in loudness causes an increase in pitch.
Hence, the difference between musical sound and noise is due to pitch.