A jingle is- A. the film score
B. the background instrumental or vocal music you hear in a TV or radio commercial
C. a song about Christmas
D. the code of a commercial​

B

Explanation:

For example, In the McDonald's radio commercial, they have a little mumble at the end that goes du-du-du-da-da and that is a Jingle!

pitch- the definition of pitch is as follows:

"the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone."