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
Out of the following hypersensitivity reactions, in which type a single dose of the antigen can act as both the sensitizing and shocking dose. 
Select and explain. 
A. Anaphylaxis, B. Arthus reaction, C. Serum sickness, D. Contact dermatitis
C: Serum sickness
Answer: C: Serum sickness 
Explanation: None