Answer:
The correct answer would be - natural active immunity.
Explanation:
Active immunity is the immunity that includes that develops antibody by the immune system after exposure to a pathogen naturally through disease or artificially by the process of immunization. This type of immunity is a long-lasting immunity.
If the active immunity is deliberately developed by exposure of antigen to the patient is called Artificial active immunity whereas natural immunity takes place through contact with a disease-causing agent.
In my opinion, natural active immunity is best as it is a fact that natural infection almost always causes better immunity than vaccines.
