Pleurocentesis, also known as thoracentesis, involves using a long needle to take a fluid sample from the pleural space, which is the area around the lungs. This procedure is typically performed to analyze pleural fluid for diagnostic purposes, such as determining the cause of fluid accumulation, and can also provide relief from symptoms like chest tightness. Therefore, the correct response is:
using a long needle to take a fluid sample of the area around the lung.