I believe the answer is D. A reactant that is catalyze a by an enzyme.
Answer:
The dry-out material contains spores of anthrax-causing bacteria
Explanation:
<em>Anthrax is a disease caused by a bacteria known as Bacillus anthracis. Susceptible animals get infected by anthrax when the spore of the bacteria gets into their bodies, become activated, multiply and produce toxins.</em>
The spore serves primarily as a propagating structure and also as an agent for transmitting infections. It can be transmitted by air, water, food or any other means. Bacterial spores usually have the capability to tolerate harsh environmental conditions and only become inactivated when conditions are favourable.
The dry granular powdery material constituent of the letters received by the U.S. senators must have been spores of <em>Bacillus anthrasis</em>
Potassium, 4 shells, 1 valence electron
The diagnosis will be variant creutzfeldt jakob disease or as called as vCJD. The variant creutzfeldt jakob disease is an intermittent and fatal human neurodegenerative illness. The ingestion of food of bovine origin contaminated with the agent of bovine spongiform encephalopathy which is a disease of cattle and has been strongly connected to the existence of vCJD in humans.