The AV node has fewer gap junctions than the SA node, leading to slower conduction. How does this slower conduction help the heart function?

• A. Ensures that the ventricles have enough time to fill with blood before they contract.
• B. Initiates the electrical impulse in the heart.
• C. Conducts the impulse rapidly to the bundle of His.
• D. Allows the ventricles to beat at a slower rate than the atria.