<h3>The answer is:</h3><h2>B</h2><h2 />
As much as Lincoln hated slavery, he owned slaves himself, meaning that if he made slavery illegal, he himself would no longer have any slaves.
After clearing that out of the way, we can solve this multiple choice question by using POE, or process of elimination:
A - It is incorrect because Lincoln owned slaves himself.
B - This is correct because this kept America peaceful at the time.
C - Again, Lincoln was against slavery.
D - Lincoln didn't believe in taxing slave states.