A 27-year-old MSM with a bacterial STI in the past year asks about doxycycline postexposure prophylaxis after condomless sex. What regimen and follow-up align with guidance?ADoxycycline 100 mg once within 24 hours; no follow-up neededBDoxycycline 200 mg once within 72 hours after sex (max 200 mg/24 h) with STI screening every 3-6 monthsCDoxycycline 100 mg BID for 7 days after each exposureDAzithromycin 1 g once after exposureENo role for antibiotic PEP for STIsCheck my answer