## **Core Concept**
The question describes a clinical scenario suggestive of a infectious disease, likely **cutaneous anthrax**, given the presence of indurated ulcers (characteristic eschar), lymphadenopathy, and systemic symptoms like fever. Cutaneous anthrax is the most common form of anthrax infection.

## **Why the Correct Answer is Right**
The correct answer involves the use of **penicillin** or other appropriate antibiotics for treating anthrax. Given that the causative organism is *Bacillus anthracis*, which is usually susceptible to penicillin, this antibiotic can be considered a first-line treatment for anthrax, especially in the early stages. The effectiveness of penicillin in treating anthrax makes option **C. Penicillin** a likely correct answer.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is blank and cannot be evaluated.
- **Option D:** This option is blank and cannot be evaluated.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that **cutaneous anthrax** often presents with a characteristic painless, indurated ulcer that eventually forms a black eschar. Early recognition and antibiotic treatment are crucial. For exam purposes, remember that **B. anthracis** is susceptible to penicillin, doxycycline, and ciprofloxacin.

## **Correct Answer:** C. Penicillin.