Final answer:
The important measure for the prevention of Hospital-Acquired Pneumonia (HAP) is the administration of pneumococcal vaccine to vulnerable individuals.
Step-by-step explanation:
The important measure for the prevention of Hospital-Acquired Pneumonia (HAP) is B) Administration of pneumococcal vaccine to vulnerable individuals. HAP is commonly caused by opportunistic bacteria, such as Klebsiella pneumoniae and Staphylococcus aureus, that are more likely to affect elderly individuals, those with preexisting lung conditions, and the immunocompromised. Vaccination against pneumococcal pathogens can help reduce the risk of HAP in vulnerable populations.