Question

what function do lungs serve within the excretory system?
remove carbon dioxide waste
remove oxygen waste
take in oxygen
take in carbon dioxide

Explanation:

The lungs are part of the excretory - respiratory system connection. During respiration, they remove carbon dioxide, a waste product of cellular metabolism, from the body. Oxygen is taken in for cellular respiration but this is not an excretory function. Carbon dioxide is the waste excreted by the lungs in the excretory system context.

Answer:

Remove carbon dioxide waste