Serum sickness is:

Ans: C. Type 3 hypersensitivity reaction(Ref: Robbins 9/e p207)Serum sickness is the prototype of a systemic immune complex disease or type III hypersensitivity reaction.Immune Complex--Mediated (Type III) Hypersensitivity:Acute serum sickness is the prototype of a systemic immune complex disease; it was once a frequent sequela to the administration of large amounts of foreign serum (e.g., serum from immunized horses used for protection against diphtheria).