Which of the following describes pleural disorders?

Pleural disorders are conditions that affect the pleura, which are the membranes surrounding the lungs and lining the thoracic cavity. The correct choice identifies fluid accumulation in the pleural space, a condition known as pleural effusion. This accumulation can occur due to various reasons, including infections, heart failure, or malignancies. It can lead to symptoms like shortness of breath, chest pain, and a sensation of heaviness, as the presence of fluid can impair lung expansion and gas exchange.

The other options focus on different respiratory issues but do not pertain specifically to pleural disorders. Decreased airflow during sleep typically relates to conditions like sleep apnea rather than pleural dysfunction. Weakness of the diaphragm is associated with neuromuscular disorders affecting respiratory function but does not describe a pleural issue. Complete cessation of airflow would imply a respiratory failure scenario, which is also distinct from disorders related to the pleura. Overall, fluid accumulation is a direct and defining characteristic of certain pleural disorders, making it the most accurate choice.