What is a round character?

Select one:

a$.$ an uncomplicated, one$-$dimensional character that does not change over the course of a movie

b$.$ an important character that is featured in every scene of a movie

c$.$ a stupid, un$-$"sharp" character that lacks edge

d$.$ a special character that comes full circle and ends up the way he or she was in the beginning of a movie

e$.$ a complex, multidimensional character that changes over the course of a movie