1. A 50-year-old male patient presents with fever, cough, and shortness of breath. Chest X-ray reveals lobar pneumonia. Which organism is the most likely cause? A. Mycoplasma pneumoniae B. Streptococcus pneumoniae C. Haemophilus influenzae D. Legionella pneumophila Answer: B. Streptococcus pneumoniae Rationale: Streptococcus pneumoniae is the most common cause of lobar pneumonia, especially in adults. It typically presents with a sudden onset of symptoms, including high fever, cough, and dyspnea. 2. A 25-year-old female patient is diagnosed with a urinary tract infection (UTI). Which factor is most likely to predispose her to recurrent UTIs? A. Use of spermicidal agents B. Frequent sexual intercourse C. History of diabetes mellitus D. All of the above Answer: D. All of the above Rationale: All listed factors can predispose individuals to recurrent UTIs. Spermicidal agents can disrupt the normal vaginal flora, frequent sexual intercourse can introduce bacteria into the urinary tract, and diabetes mellitus can impair the immune response. 3. During an outbreak of viral gastroenteritis at a local school, which of the following measures is most effective in preventing the spread of infection? A. Administration of antibiotics to all students B. Thorough handwashing with soap and water C. Isolation of symptomatic individuals only D. Vaccination of all students and staff Answer: B. Thorough handwashing with soap and water Rationale: Hand hygiene is the most effective way to prevent the spread of viral gastroenteritis. Antibiotics are not effective against viruses, and while isolation and vaccination can help, they are not as immediately impactful as proper handwashing. 4. A patient with tuberculosis (TB) is started on a standard treatment