This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
Immunity by vaccination is 
Select and explain. 
A. Active natural, B. Passive natural, C. Active acquired, D. Passive acquired
C: Active acquired
Answer: C: Active acquired 
Explanation: Active immunity occurs as a result of infection or by specific immunization and is usually associated with the presence of antibodies or cells having a specific action on the microorganism or on its toxin. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 109