Read this sentence from the final paragraph: One thing we know for certain, much like the outrageous monsters we conjure in our worst nightmares, the deep ocean is an equally imaginative source of shock, awe, and outright fright.

What is the purpose of this sentence in the paragraph?

A) To connect two supporting ideas

B) To compare two unrelated creatures

C) To introduce a new topic and point

D) To summarize the main point of the article