Acquired immunity is developed through which of the following methods?

Acquired immunity refers to the immunity that develops after exposure to a pathogen or through vaccination. This type of immunity is not present at birth but is built up as the immune system encounters various antigens. Overcoming diseases allows the immune system to recognize and remember specific pathogens, leading to a stronger and quicker response upon subsequent exposures. Similarly, vaccinations introduce a harmless form of a pathogen or its components, stimulating the immune system to develop a memory against it without causing the disease. This process is crucial for providing long-term protection against infectious diseases.

In contrast, other options like genetic predisposition relate to inherited traits which do not result in acquired immunity, while natural environmental exposure does not specifically lead to immunity unless it involves a pathogen that the immune system can learn from. A consistent healthy diet, while important for overall health and immune function, does not independently lead to acquired immunity.