**Core Concept**
The treatment of chlamydia and gonorrhea involves using antibiotics that target the causative pathogens. Chlamydia trachomatis is a bacterium that causes chlamydia, while Neisseria gonorrhoeae causes gonorrhea. The choice of antibiotic is crucial to ensure effective treatment and prevent antibiotic resistance.

**Why the Correct Answer is Right**
The combination of azithromycin and ceftriaxone is the recommended treatment for chlamydia and gonorrhea. Azithromycin is a macrolide antibiotic that targets Chlamydia trachomatis, while ceftriaxone is a cephalosporin antibiotic that targets Neisseria gonorrhoeae. This combination is effective because it covers both pathogens and helps prevent the development of antibiotic resistance.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not include a macrolide antibiotic to target Chlamydia trachomatis.
* **Option B:** This option is incorrect because it does not include a cephalosporin antibiotic to target Neisseria gonorrhoeae.
* **Option D:** This option is incorrect because it does not include a macrolide antibiotic to target Chlamydia trachomatis.

**Clinical Pearl / High-Yield Fact**
When treating chlamydia and gonorrhea, it is essential to use a combination of antibiotics that target both pathogens to prevent antibiotic resistance and ensure effective treatment.

**Correct Answer:** C. Azithromycin and ceftriaxone.