Which of the following indicates a decreased lung compliance?

Decreased lung compliance refers to the lungs' reduced ability to expand during inhalation. This can occur due to lung stiffness or any condition that limits the lung's ability to stretch and fill with air. In the case of ARDS (Acute Respiratory Distress Syndrome), the lung tissue becomes inflamed and fluid-filled, significantly affecting its elasticity and compliance. As a result, patients with ARDS struggle to take in adequate amounts of air, reflecting a marked decrease in lung compliance.

The other options represent different conditions or activities that do not specifically indicate decreased lung compliance. For instance, hyperventilation typically involves increased lung compliance as a response to anxiety or metabolic demands, while mild asthma may show some restrictions but usually does not exhibit the same level of compliance issues as ARDS. Coughing is a reflex action that can occur regardless of lung compliance, often serving to clear secretions but not directly indicating compliance levels. Thus, ARDS stands out as the condition that directly signifies decreased lung compliance.