Write the next sentence in the following story.

How to diagnose bloat in great danes
Look for swelling.
Your dog's stomach may be swollen if it makes a tympanic, drum-like sound when you flick it. This means the stomach is full of gas.

Pick your answer from:
(A). When you flick the area, it will become swollen. It may also come up while it is eating or drinking..
(B). This if is accompanied by dark red, lump-like fluid. With the upper abdominal portion enlarged, pus (pus and pus turn up on the dog's belly, then/or draining into the fecal canal) will accumulate on the upper abdomen..
(C). Swelling is one common symptom that persists for longer than two hours. Pay attention to swelling around your dog's jaw..
(D). While swelling is the most obvious symptom of bloat, it can be difficult to spot in great danes because of their large size. If you're unsure whether your great dane has a swollen stomach, discuss your concerns with a veterinarian rather than wait for symptoms to improve... The answer should be
(D).