Why are some of President Lincoln’s ideas considered contradictory?

Lincoln did not believe he had the power to end slavery because it was evil, but he believed he could end it to preserve the Union. He worked with the radicals but also resisted them, he used them as he did with the conservatives. As chief magistrate he made a clear distinction between his personal beliefs and his official actions.

i would say your answer is a)

sorry if im wrong

disease was the number one killer of native peoples. they had had little exposure to the diseases of europe. this led to some villages being almost completely wiped out and some tribes destroyed.