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
Anaphylaxis refers to the: 
Select and explain. 
A. Severe reaction following the injection of protein solutions in a sensitised individual, B. Severe reaction following primary injection of protein solutions, C. State of immunity developed by repeated injections of any foreign substance, D. Severe reaction resulting from sensitivity to common allergens
A: Severe reaction following the injection of protein solutions in a sensitised individual
Answer: A: Severe reaction following the injection of protein solutions in a sensitised individual 
Explanation: Prince of Monaco first observed the deleterious effects of jellyfish on bathers. 
Subsequently, Portier and Richet (1906) suggested a toxin to be responsible for these effects and coined the term “anaphylaxis”.

Initiator cells in anaphylaxis
The initiator of type I reaction is otherwise known as allergen.
Typical allergens include:

Plant pollen
Proteins (e.g., foreign serum and vaccines)
Certain food items (e.g., eggs, milk, seafood, and nuts)
Drugs (e.g., penicillin and local anesthetics)
Insect products (venom from bees, wasps, and ants)
Dust mites and mould spores
Animal hair 
Dander

Parija SC. Textbook of Microbiology & Immunology. Elsevier Health Sciences; 2014. Page:149-150