**Core Concept**
The patient's presentation suggests a diagnosis of **Leptospirosis**, a zoonotic infection caused by the bacterium *Leptospira*. This condition can lead to **renal failure** and **hepatic dysfunction**, as evidenced by the patient's symptoms and lab results.

**Why the Correct Answer is Right**
The preferred antibiotic for treating Leptospirosis is **Penicillin** or **Doxycycline**, as they are effective against *Leptospira* and can help prevent long-term complications. However, the correct answer choice is not provided, but typically, **Doxycycline** is a common choice due to its efficacy and safety profile.

**Why Each Wrong Option is Incorrect**
**Option A:** May not be the correct choice without knowing the specific option, but generally, **Cephalosporins** or **Fluoroquinolones** might not be the first-line treatment for Leptospirosis.
**Option B:** Similarly, without the specific option, it's difficult to comment, but **Macrolides** are not typically used as first-line treatment for Leptospirosis.
**Option D:** Again, without the specific option, it's challenging to provide a detailed explanation, but **Aminoglycosides** might not be the preferred choice due to their potential nephrotoxicity, which could exacerbate renal failure.

**Clinical Pearl / High-Yield Fact**
In patients with suspected Leptospirosis, especially those with renal or hepatic involvement, prompt antibiotic treatment is crucial to prevent long-term sequelae. Remember, **Doxycycline** is often used for prophylaxis and treatment in certain cases.

**Correct Answer:** D. Doxycycline