Final answer:
Louis Armstrong was not a contributor to the bebop style of the 1940s; rather, Charlie Parker, Dizzy Gillespie, and Thelonious Monk were key figures in the development of bebop.
Step-by-step explanation:
The bebop style of jazz that emerged in the 1940s was characterized by its fast tempos, complex chord progressions, and improvisation.
The correct answer to the question of who was NOT a contributor to the bebop style is c) Louis Armstrong. While Armstrong was an incredibly influential jazz musician, his peak era was earlier, and his style did not align with the bebop movement.
Notable contributors to bebop include Charlie Parker, Dizzy Gillespie, and Thelonious Monk, who are all known for being pioneers of this genre.