I believe it is B. Hope this helps!!
Answer: By the number of legs it has.
Explanation: Millipedes have hundreds of legs while centipedes have way less.
The impact in this case is the ventricles will beat more slowly.
Sinoatrial node acts as a pace maker for the heart skipping the plateau phase and the electric impulses are created here. This node lets the blood into ventricles.
Atrioventricular node acts as controller of heart rate and serves as an electrical relay station. This node connects the right atrium and right ventricle.
