_______ is usually expressed as a simple, declarative sentence that refines and sharpens the specific purpose statement .

A thesis statement refers to _____. A: a simple, declarative sentence that refines and sharpens the specific purpose B: an example that supports the idea a speaker intends to talk about C: something that illustrates, consolidates, and/or, expands the central idea D: a statement that lets the audience know the topic of the speech