Answer:
i don't know
Explanation:
i hope someone else can help you
Filmmakers most likely chose this name because it was about the Selma to Montgomery marches that Dr. King participated in. The name is Selma and not Dr. King because it is a story told over a three month period where Dr. King and many others planned the Selma marches.
I hope this helped you! Feel free to add more ideas to it!