Answer: d) Minocycline* Resistant strains of P. acnes are emerging that may respond to judicious use of retinoids in combination with antibiotics.* Commonly used topical antimicrobials in acne include erythromycin, clindamycin and benzoyl peroxide and antibiotic-benzoyl peroxide combinations.* Other antimicrobials used in treating acne include sulfacetamide, sulfacetamide/sulfur combinations, metronidazole, and azelaic acid.* Systemic therapy is prescribed for patients with more extensive disease and acne that is resistant to topical therapy.* Effective agents include tetracycline, minocycline, erythromycin, clindamycin, and trimethoprim- sulfamethoxazole.* Antibiotics usually are administered twice daily, and doses are tapered after control is achieved.* Tetracycline is the most commonly employed antibiotic because it is inexpensive, safe, and effective.* Its efficacy in acne may be more dependent on its antiinflammatory activity.* Tetracycline may make the skin more sensitive to sunlight.* Photosensitivity is more common with doxycycline and less common with minocycline.* Minocycline has better gastrointestinal absorption and is highly effective.* With all the tetracyclines, vaginal candidiasis is a common complication that is readily treated with local administration of antifungal drugs.