The heartbeat originates at the

a. SA node

b. AV node

c. Bundle of His

d. Purkinje fibers

SA node

Explanation:

The human heart beats 72 times per minute. The heartbeat originates in the neuromuscular tissues of the heart. There are different neuromuscular tissue such as SA node, AV node, the bundle of his, and Purkinje fibers. The heartbeat first generates at the SA node. Therefore, this is called the pacemaker of the heart. The SA node present in the right atrium and near to the superior vena cava. The heartbeats are nothing but the electrical impulse which passes in the heart. It originates at the SA node and transfers to the AV node. Then it transfers to the bundle of his and finally reaches to the Purkinje fiber.