**Core Concept**
The question is testing the concept of immune memory, specifically the cells responsible for long-lasting immune protection against a particular pathogen. This concept is crucial in understanding the body's ability to mount a rapid and effective response to future infections.

**Why the Correct Answer is Right**
The correct answer is T cells, specifically memory T cells, which play a key role in providing long-lasting immune protection against a particular pathogen. Memory T cells are a type of T lymphocyte that has been previously activated to recognize and respond to a specific antigen. They are able to recognize and respond to the same antigen more quickly and effectively than naive T cells, providing long-lasting immunity against future infections. This is achieved through the formation of immunological memory, which allows the immune system to "remember" past infections and mount a rapid response upon re-exposure to the same pathogen.

**Why Each Wrong Option is Incorrect**
**Option A:** B cells are responsible for producing antibodies, which provide short-term immunity against a particular pathogen. While B cells play a crucial role in the immune response, they are not responsible for long-lasting immune protection.
**Option B:** Macrophages are a type of white blood cell that plays a key role in the innate immune response, but they are not responsible for long-lasting immune protection against a particular pathogen.
**Option C:** Dendritic cells are a type of antigen-presenting cell that plays a key role in the initiation of the adaptive immune response, but they are not responsible for long-lasting immune protection against a particular pathogen.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that memory T cells are responsible for long-lasting immune protection against specific pathogens, and their activation can lead to the development of immunological memory, allowing the immune system to mount a rapid response upon re-exposure to the same pathogen.

**Correct Answer:** C. T cells.