Which of the following is a third generation oral cephalosporin?

Cefdinir is classified as a third-generation oral cephalosporin. This generation of cephalosporins typically has increased activity against gram-negative bacteria compared to earlier generations and retains good efficacy against gram-positive organisms. Third-generation oral cephalosporins like cefdinir are often used for the treatment of respiratory tract infections, skin infections, and some other mild to moderate infections due to their favorable pharmacokinetics and spectrum of activity.

In contrast, the other options provided are different generations or types of cephalosporins. Cefepime, for instance, is a fourth-generation cephalosporin known for its broader spectrum and improved stability against beta-lactamases. Cefotetan and cefoxitin are both second-generation cephalosporins, which are typically used to treat infections caused by anaerobic bacteria or for surgical prophylaxis, offering less gram-negative coverage than third-generation cephalosporins like cefdinir. Therefore, selecting cefdinir is appropriate when identifying a third-generation oral cephalosporin.