Which of the Following Is True of Cardiac Muscle

Which of the following is true of cardiac muscle?

A) Cardiac muscle tissue has both an intracellular and extracellular source of Ca⁺⁺.
B) Cardiac muscle tissue has slow Ca⁺⁺ voltage gates in the membrane that make cardiac muscle incapable of tetanus.
C) In cardiac muscle tissue, excitation spreads from cell to cell via intercalated disks.
D) Cardiac muscle tissue does not require nerve activity to stimulate a contraction.
E) All of these are true of cardiac muscle.