Anthrax is the disease known as splenic fever — option 2.

Where the name comes from. In animals dying of anthrax the spleen becomes greatly enlarged, dark and soft, and this was the most striking finding at post-mortem long before the cause was understood. Veterinarians therefore called the disease splenic fever or splenic apoplexy. The name “anthrax” is from the Greek for coal, after the black scab that forms in the skin form of the disease.

Why anthrax is so important in the history of science. It was the first disease for which a specific bacterium was proved to be the cause. Robert Koch demonstrated the complete life cycle of Bacillus anthracis in 1876 and used it to establish the germ theory of disease and the postulates that bear his name. Five years later Louis Pasteur gave his famous public demonstration at Pouilly-le-Fort, vaccinating sheep against anthrax and showing that the vaccinated animals survived while the controls died — the first laboratory-made vaccine against a bacterial disease.

The three forms in humans. Cutaneous anthrax, contracted through a cut while handling hides or wool, is the commonest and least dangerous. Gastrointestinal anthrax follows eating infected meat. Inhalational anthrax, sometimes called woolsorters’ disease, comes from breathing in spores and is the most lethal. The spores can survive in soil for decades, which is why outbreaks recur in the same grazing grounds and why carcasses of animals dying of anthrax must be burned or buried deep rather than skinned.

Hence, the answer is Anthrax.