Question

what is the purpose of the air sacs attached to birds lungs? to store air to ensure oxygen is always present to inflate and deflate to help a bird during take - off and landing to inflate to help make the bird more buoyant to deflate to help the bird lower in altitude when flying

Explanation:

Birds have a unidirectional respiratory system. Their air sacs act as reservoirs, storing and moving air through the lungs continuously. This ensures a constant supply of oxygen, which is critical for the high metabolic demands of flight, unlike the other options which do not describe the primary respiratory function of these sacs.

Answer:

A. To store air to ensure oxygen is always present