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: Social & Preventive Medicine
Antisera is obtained from 
Select and explain. 
A. Guinea pig, B. Horse, C. Rat, D. Rabbit
B: Horse
Answer: B: Horse 
Explanation: Antisera (Antitoxins): Materials prepared in animals; non-human sources like horses