Which of the following about the controlling idea is not true?
选项：

A:A paragraph is a sentence or group of sentences that support one main idea. That’s what we call the “controlling idea” because it controls what happens in the rest of the paragraph.
B:It is always the first sentence.
C:It is about the most important idea that you are trying to convey to your reader in a paragraph.
D:The information in each paragraph must be related to that idea.