This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
A man, after skinning a dead animal, developed a pustule on his hand. A smear prepared from the lesion showed the presence of Gram positive bacilli in long chains which were positive for McFadyean's reaction. The most likely aetiological agent is- 
Select and explain. 
A. Clostridium tetani, B. Listeria monocytogenes, C. Bacillus anthracis, D. Actinomyces sp
C: Bacillus anthracis
Answer: C: Bacillus anthracis 
Explanation: None