Which type of immunity is developed after surviving an infection?

The correct type of immunity developed after surviving an infection is active natural immunity. This form of immunity occurs when an individual's immune system is exposed to a pathogen during the course of an infection, leading to the production of specific antibodies and memory cells tailored to that pathogen. As a result, if the same pathogen re-enters the body in the future, the immune system can respond more efficiently and effectively because it "remembers" the previous encounter.

Active natural immunity is characterized by a longer-lasting immune response compared to other types of immunity, as it involves the body's own immune system actively generating a defense against the pathogen. This contrasts with passive immunity, where antibodies are transferred from one individual to another rather than being produced by the host's own immune system.

In this scenario, options that involve passive immunity—whether natural or artificial—do not result from the individual's own immune response to an infection, making them irrelevant to the question. Active artificial immunity, such as that gained through vaccination, also involves the immune response but differs in that it is intentionally introduced rather than resulting from an actual infection. Thus, active natural immunity is the most appropriate term for immunity gained from surviving an infectious process.