A. Amoxicillin/clavulanate (Augmentin): Amoxicillin/clavulanate is a broad-spectrum antibiotic but not the preferred choice for anthrax exposure. B. Nystatin (Mycostatin): Nystatin is an antifungal medication used for treating fungal infections, such as oral thrush or cutaneous candidiasis. It is not effective against anthrax, which is a bacterial infection. C. Ciprofloxacin (Cipro): Ciprofloxacin, a fluoroquinolone, is the recommended first-line antibiotic for treating anthrax exposure due to its efficacy against Bacillus anthracis, the bacteria causing anthrax. D. Tamoxifen: Tamoxifen is a selective estrogen receptor modulator (SERM) used primarily in the treatment of breast cancer. It has no role in treating bacterial infections like anthrax.