Which plane separates the abdominal cavity from the thoracic cavity?

The transverse plane, also known as the horizontal plane, is the anatomical plane that divides the body into superior (upper) and inferior (lower) parts. In the context of the human body, it separates the abdominal cavity from the thoracic cavity. The diaphragm, a muscular structure that plays a key role in respiration, marks the boundary between these two cavities.

When considering the other planes: the sagittal plane divides the body into right and left sections, which does not serve to distinguish between the abdominal and thoracic cavities. The coronal plane separates the body into anterior (front) and posterior (back) regions, which also does not directly address the separation of the abdominal and thoracic areas. Lastly, the frontal plane is another term for the coronal plane, further confirming that it does not relate to the specific division of these two cavities. Thus, the transverse plane is the correct answer as it accurately represents the anatomical separation between the thoracic and abdominal cavities.