This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Introduction, Subject name: Pediatrics
Antisera is obtained from: 
Select and explain. 
A. Guinea pig, B. Rabbit, C. Rat, D. Horse
D: Horse
Answer: D: Horse 
Explanation: ANTISERA: -Antisera are usually prepared in horses -provide passive immunization - Immunoglobulin fraction is concentrated using ammonia sulfate & some products are fuher treated with some enzymes to decrease reactions to foreign proteins. -Antisera are used against diseases like Diphtheria, Tetanus, Rabies.