## Core Concept
Anthrax is a bacterial infection caused by *Bacillus anthracis*, a gram-positive, rod-shaped bacterium. It primarily affects the skin, lungs, and gastrointestinal tract. Understanding its pathogenesis, transmission, and clinical manifestations is crucial for diagnosis and management.

## Why the Correct Answer is Right
The correct answer, which is not provided, would typically relate to a characteristic or aspect that is not true about anthrax. Generally, *Bacillus anthracis* is known for its ability to cause cutaneous, inhalational, and gastrointestinal anthrax. It produces toxins that inhibit protein synthesis and cause cell death. The bacteria are usually susceptible to penicillin, ciprofloxacin, and doxycycline.

## Why Each Wrong Option is Incorrect
- **Option A:** Without specific details on option A, it's challenging to provide a direct explanation. However, if option A states something accurate about anthrax, such as its causative agent (*Bacillus anthracis*), mode of transmission (inhalation, ingestion, or skin contact), or clinical manifestations (cutaneous, inhalational, or gastrointestinal symptoms), then it would not be the correct answer to the "all except" question.
- **Option B:** Similarly, if option B presents a true statement about anthrax, such as its potential for bioterrorism, the importance of prompt antibiotic treatment, or the existence of a vaccine, it would be incorrect as the "all except" option.
- **Option C:** If option C provides an accurate description of anthrax, such as the role of anthrax toxin in pathogenesis or the typical incubation period, it would not be the correct choice for the exception.
- **Option D:** This option would also be incorrect if it accurately describes a feature of anthrax, such as the bacteria's gram-positive nature or the potential for high mortality if untreated.

## Clinical Pearl / High-Yield Fact
A key point to remember about anthrax is that **cutaneous anthrax**, which occurs through skin contact with anthrax spores, is the most common form and often presents as a painless skin ulcer with a characteristic black eschar. Early recognition and antibiotic treatment significantly improve outcomes.

## Correct Answer: D.