Which jazz style emerged in the 1940s and featured smaller groups and more complex chord changes? A. swing
B. ragtime
C. bebop
D. New Orleans jazz

Bebop

Explanation: Bebop or bop is a style of jazz developed in the early to mid-1940s in the United States, which features compositions characterized by a fast tempo, complex chord progressions with rapid chord changes and numerous changes of key, instrumental virtuosity, and improvisation based on a combination of harmonic structure

i think the answer is disc jockeys