A  

Concise reasoning:  
• Lamivudine alone is not recommended; current PEP guidelines call for at least a two-drug backbone (e.g., zidovudine + lamivudine) and often a third agent, so statement a is false [USPHS, 2001, PMID 11442229].  
• Immediate washing of the wound with soap and water is advised after any needlestick, so statement b is true [Chogle et al., 2002, PMID 12044118].  
• Baseline (“viral markers”) HIV/HBV/HCV testing of the exposed worker is performed at the time of the incident, so statement c is true [USPHS, 2001, PMID 11442229].  
• Follow-up HIV serology at 6 weeks (in addition to later tests) is specifically recommended, making statement d true [USPHS, 2001, PMID 11442229].