Final answer:
The example of artificially acquired active immunity is vaccination, as it involves administering weakened or inactivated pathogens to provoke an adaptive immune response, creating immunological memory without causing illness.
Step-by-step explanation:
An example of artificially acquired active immunity is c. vaccination. This involves the intentional introduction of a vaccine, which contains a killed or weakened form of a pathogen or just key antigens, to stimulate an individual's immune system to develop adaptive immunity, including the formation of memory cells. Unlike passive immunity where antibodies are directly given to an individual, active immunity ensures long-term protection by enabling the body to produce its own antibodies in response to the presence of the antigens.
Artificially acquired active immunity is a cornerstone of preventive medicine, leading to the eradication or control of several infectious diseases such as smallpox, polio, measles, and whooping cough. The immune memory created by vaccination prevents the vaccinated individual from becoming ill if they encounter the actual pathogen in the future.