This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Which amongst the following biological agents has the highest potential for use as a vector in bioterrorism 
Select and explain. 
A. Plague (Yersinia pestis), B. Small pox (variola major), C. Botulism (Cl. Botulinum), D. Brucellosis (Brucella sp)
A: Plague (Yersinia pestis)
Answer: A: Plague (Yersinia pestis) 
Explanation: Plague - this disease has a history of its use in biological warfare dating back many centuries and is considered a thread due to its ease of culture and ability to remain in circulation among local rodents for a long period of time. Ref: Baveja textbook of microbiology; 4th edition