Which statement best describes intrinsic conduction of the heart?

• A. Cells within the heart can initiate and transmit action potentials without nervous system input.
• B. Cells in the heart can beat continually without fatigue.
• C. Cells in the heart follow a specific rhythm that is set by the brain stem.
• D. Cells in the heart pass action potentials between cells using gap junctions instead of neurotransmitters.