Independent proof method and reduction to absurdity are two methods of indirect argumentation.The independent proof method is to prove that the proposition that contradicts the refuted proposition is true, thereby confirming that the refuted proposition is false. Reduction to absurdity means that the proposition to be refuted is true, leading to an absurd conclusion, thereby proving that the proposition to be refuted is false.
According to the above definition, which of the following uses the independent proof method?
A: Human nature is evil. B: If human nature is evil, then where does the moral code come from?