The problem of electrical discontinuity caused in the normal heart by the connective tissue ...

The problem of electrical discontinuity caused in the normal heart by the connective tissue separating the atria from the ventricles is solved by
 a. having the A-V node function as a secondary pacemaker.
  b. having an ectopic pacemaker.
  c. coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the vagus nerve.
  d. coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the bundle of His.
  e. coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the Purkinje fibers.