A 20-year-old college student presents for evaluation of cough and fever. He states that he started feeling ill several days ago. His symptoms include fever (100.5°F), headache, and body aches. He has missed 2 days of classes and is feeling worse. He has tried a few over-the-counter cough and cold medications without relief. Several other students have been ill on campus. On examination, there is a frequent cough but overall, he does not appear in any distress or discomfort. Vital signs show a temperature of 100.5°F, pulse 90 beats/min, and respiratory rate 22 breaths/min. His pharynx is injected; otherwise, a head and neck examination is normal. His lung examination is notable only for some scattered rhonchi. The remainder of his examination is normal. Chest radiography shows some patchy infiltration. A sputum Gram stain shows white blood cells but no organisms. What antibiotic class is considered first line for treatment of his condition?

(A)          Cephalosporins

(B)          Fluoroquinolones

(C)          Macrolides

(D)          Penicillins

(E)          Carbapenems