The heart is controlled through an intrinsic electric system, normally activated in which order?
a. SA node, AV node, bundle branches, bundle of His, Purkinje fibers
b. AV node, SA node, bundle of His, bundle branches, Purkinje fibers
c. AV node, SA node, Purkinje fibers, bundle branches, bundle of His
d. SA node, AV node, bundle of His, bundle branches, Purkinje fibers
Answer: D