I think the answer is B. As long as the clause after the colon is independent, you can capitalize it.
Definition<span> of </span>Anthropomorphism<span>. </span>Anthropomorphism<span> is a </span>literary<span> device that can be </span>defined<span> as a technique in which a writer ascribes human traits, ambitions, emotions or entire behavior to animals, non-human beings, natural phenomena or objects.</span>
