To answer this question, it is important to understand that the question is actually a play on words or a joke.
When you divide a loaf (a type of bread) by a knife, you are not performing a mathematical division. Instead, the answer is intended to be a humorous response related to bread.
Option A) I don't know - This option is incorrect because it does not provide the intended humorous response.
Option B) There's no answer - This option is incorrect because it does not provide the intended humorous response.
Option C) Bread and butter - This option is correct because it is a common phrase used to describe something that is essential or basic. In this context, it is a pun referring to the question about dividing bread with a knife.
Option D) Don't waste my time!! - This option is incorrect because it does not provide the intended humorous response.
The correct answer is C) Bread and butter. This option is correct because it provides the intended humorous response related to bread.