I guess the paragraph break should be after the B) Ellen asked and "How are you feeling?" and Ellen said. Because while reading this dialog, reader need a pause between the information which these characters exchange. In my opinion, there must be graphical and emotional space between their introduction and next action that hasn't revealed yet. Also, I'd choose B to make this conversation looks alive.
The subject is sponge because that is what is the main point of the sentence is.
Answer:
Heart
Explanation:
Hemlock can be poison
crows are mysterious and black
As for dust, there's the saying "From dust we come, to dust we shall return."
