Question

the skin is a part of which body system?
the excretory system
the respiratory system
the cardiovascular system

Explanation:

The excretory system is responsible for removing waste from the body. The skin excretes sweat (containing waste like urea, salts) as part of excretion. The respiratory system focuses on gas exchange (lungs), and the cardiovascular system on blood circulation (heart, blood vessels). So the skin is part of the excretory system.

Answer:

A. the excretory system