Final answer:
The term 'Immunity' relates to the body's ability to protect itself from disease through the formation of memory lymphocytes, characterizing the adaptive immune system's active immunity, which consists of specificity and memory. The correct option is b.
Step-by-step explanation:
Immunity is the ability of the body to protect itself from disease. When responding to the question posed, the correct answer is b. Immunity. This term refers to the body's ability to resist a pathogen due to the formation of memory lymphocytes (B or T cells) to that specific pathogen.
The body's adaptive immune system is capable of developing active immunity, which is the ability to resist a specific pathogen that results from an immune response that produces memory lymphocytes for that pathogen.
Active immunity is an adaptation that occurs during the lifetime of an individual as an adaptation to infection with a specific pathogen, preparing the immune system for future challenges from that pathogen.
Active immunity can be acquired naturally, for example, after recovering from an infection like chickenpox, the body develops a memory of the infection that will specifically protect it from the causative agent, the varicella-zoster virus if exposed to it again.
This demonstrates both the specificity and memory aspects of adaptive immunity. Conversely, passive immunity results from the transfer of antibodies to a person who has not been exposed to the pathogen, which does not involve the formation of memory cells. The correct option is b.