The correct answer is option 1: Four. The human heart consists of four chambers. These chambers are divided into two sections, the right and left sides of the heart. Each side has two chambers: an upper chamber called the atrium and a lower chamber called the ventricle. The right atrium receives oxygen-poor blood from the body, which then flows into the right ventricle. The right ventricle pumps this oxygen-poor blood to the lungs for oxygenation. Oxygen-rich blood from the lungs then enters the left atrium and flows into the left ventricle. The left ventricle is responsible for pumping oxygen-rich blood to the rest of the body. This four-chamber setup allows for efficient circulation of blood throughout the body.