This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of skin, Subject name: Dental
Normal commensal of skin is 
Select and explain. 
A. Candida, B. Propionibacterium, C. Clostridia, D. TB
B: Propionibacterium
Answer: B: Propionibacterium 
Explanation: Its members are primarily facultative parasites and commensals of humans and other animals, living in and around the sweat glands, sebaceous glands, and other areas of the skin. One study found the Propionibacterium was the most prevalent human skin-associated genus of microorganisms Ref Harrison20th edition pg 1208