Artificial Active Immunity via Vaccination

Steps:

• Recall immunity types: active involves body producing antibodies; passive receives pre-formed ones.
• Distinguish artificial from natural: artificial uses external agents like vaccines, not infection.
• Identify vaccine role: contains antigens to stimulate immune response without disease.
• Match to options: seek description of antigen stimulation from vaccine, not antibodies or natural sources.

Why C is correct:

• Artificial active immunity is defined as the deliberate stimulation of lymphocytes by vaccine antigens, prompting the body to produce its own antibodies and memory cells.

Why the others are wrong:

• A describes artificial passive immunity, where pre-formed antibodies are injected.
• B describes natural passive immunity, transferring antibodies via colostrum from mother to infant.
• D describes natural active immunity, triggered by antigens from actual pathogen invasion.

Final answer: C