Research the instrument and explain how it works in terms of sound production and resonance. Describe how a musician can vary the pitch and loudness of the notes. Explain why different types of musical instruments sound different, even though they play the same notes.

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere. the winds blow from west to east in jet streams but the flow often shifts to the north and south. jet streams follow the boundaries between hot and cold air. the earth's rotation is responsible for the jet stream as well.

It is d, all the other ones say incorrect answer .