This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood, Subject name: Pathology
Transfusion reaction and erythroblastosis fetalis are- 
Select and explain. 
A. Type I hypersensitivity, B. Type II hypersensitivity, C. Type III hypersensitivity, D. Type IV hypersensitivity
B: Type II hypersensitivity
Answer: B: Type II hypersensitivity 
Explanation: Ans. is 'b' i.e., Type II hypersensitivity Schick test is an example of type III hypersensitivity or immune-complex reaction.HYPERSENSITIVITYType I (IgE mediated)Type II (IgG IgM ando Eczemacomplement mediated)o Hay fevero Blood transfusion reactionso Asthmao Erythroblastosis fetaliso Atopyo Autoimmune hemolytico Urticariaanemia or thrombocytopeniao Anaphylactic shockor agmulocytosiso Acute dermatitiso Pemphigus vulgariso Theobald smitho Good pasture syndromephenomenono Bullous pemphigoido Prausnitz Kusntero Pernicious anemia(PK) reactiono Acute rheumatic fevero Casonis testo Diabetes mellituso Schultz-Daleo Graves diseasephenomenono Myasthenia gravisHYPERSENSITIVITYType III flgG IgM. complementType IV (Cell mediated)and leucocyte mediated)o Tuberculin testo Local-Arthus reactiono Lepromin testo Systemic-serum sicknesso Sarcoidosiso Schick testo Tuberculosiso Polyarteritis nodosa (PAN)o Contact dermatitiso Rheumatoid arthritiso Granulomatous inflammationo SLEo Type I lepra reactiono Acute viral hepatitiso Patch testo Penicillamine toxicityo Temporal arteritiso Hyperacute graft rejectiono Jones mote reactiono Type 2 lepra reaction (ENL)(cutaneous basophilic HSN)o Hypersensitivity pneumonitiso Graft rejectiono R.A.o Fairleys testo Infective endocarditiso Frie's testo Henoch schonlein purpura o Glomerulonephritis