In the Infamous Anthrax Attacks of 2001, Several Letters Were

In the infamous anthrax attacks of 2001, several letters were received at the offices of two U.S. senators and various news media outlets. The letters contained dry granular or powdery material. Seventeen people who came into contact with the material from the letters suffered anthrax infections; five more died of anthrax. How could dried-out material cause anthrax?

A) Anthrax bacteria are acellular infectious particles. When they came into contact with living hosts, they entered the hosts' cells, took over their metabolic machinery, and caused them to produce more bacteria.
B) Anthrax bacteria can form endospores under harsh environmental conditions. The material in the letters contained endospores of anthrax bacteria, which germinated and grew in the more favorable environment of the victims' bodies.
C) Anthrax bacteria can form endospores in order to reproduce. A few active bacteria in the letters started to produce enormous numbers of endospores upon contact with the anthrax victims.
D) Anthrax endospores are highly motile by flagella. When the endospores came into contact with human hosts, they swarmed into the bodies of their victims.
E) None of the choices are correct.