Understanding Protagonist's Moral Ambiguity

Consider the following excerpt from a literary analysis:

In her novel, the author constructs a protagonist whose moral ambiguity challenges traditional notions of heroism. The character's decisions, often driven by personal gain, compel the reader to scrutinize the very definition of virtue. By juxtaposing this character with a foil representing unwavering morals, the author not only highlights the complexities of ethical dilemmas but also critiques the binary view of good versus evil.

Which of the following best captures the essence of the protagonist's role in the narrative as described above?