Biology

Answer: C

Explanation:

Correct option (C): Vaccination involves introducing a weakened, inactivated, or part of a pathogen (antigen) into the body.
This stimulates the immune system to produce an immune response, including the formation of memory cells.
Since this is an artificial way (through vaccination) of triggering the body's own immune system to actively respond and develop immunity, it is artificial active immunity.

Incorrect option (A): Natural active immunity occurs when a person gets infecte...