Answer: C
Explanation: A thesis is a statement or theory that is put forward as a premise to be maintained or proved. This is often used in an argument, but you always have to prove it. A thesis statement summarizes the main point or claim. Example: Peanut butter and jelly sandwiches are the best type of sandwich because they are versatile, easy to make, and taste good.
A is incorrect. Yes, you should make the answer obvious, but that is not all to it.
B is incorrect. No thesis statement is "too large." The more information, the better.
D is incorrect. The definition of vague is, uncertain, indefinite, or unclear character or meaning. You ALWAYS want your thesis to be certain and clear. Using first person should be avoided. Normally when others use first person, your saying "I think", "I believe", which doesn't make your statement certain.