What is TRUE about the genre known as hot jazz? Multiple musicians use improvisation at the same time.

Only one instrument at a time is allowed to improvise.

Improvisation is not permitted; the score is unchanged.

The "frontline" instruments are used less than previous styles.

Multiple musicians use improvisation at the same time.

Explanation:

Hot jazz can also be called Dixieland, and it can also be called traditional jazz. It is a subgenre of Jazz, but its differential is the constant improvisation of all musicians and singers, who can even improvise simultaneously, giving a bohemian tone, freedom, fun and diversity to music, different from New Orleans Jazz that it presented a fixed musical structure, where all the musicians followed melodies and compositions strictly established for each one of them.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain