The one central idea of I know why the caged bird sings is people without much education can be as wise as well-educated people. Thus the last option is correct.
The central idea of any literature piece defines the main idea and highlights what will go to take place in the story. It helps the audience to understand the plot by connecting with the events.
The main theme of I Knows Why the Caged Bird Sings is that people with less education can be just as wise as people with higher knowledge because she feels caged due to discrimination.
Learn more about Caged bird, here:
https://brainly.com/question/10441603
#SPJ4