**Core Concept**
Plasma cells are a type of white blood cell that plays a crucial role in the adaptive immune response. They are responsible for producing and secreting large amounts of antibodies, which are proteins that help to neutralize or remove pathogens from the body.

**Why the Correct Answer is Right**
Plasma cells are derived from B lymphocytes (B cells), a type of immune cell that recognizes and binds to specific antigens. When a B cell encounters its specific antigen, it undergoes a process called activation, which leads to its differentiation into a plasma cell. Plasma cells then produce and secrete antibodies that are specific to the antigen that activated them. This process is a key part of the humoral immune response.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because plasma cells are not derived from T lymphocytes (T cells), which are a different type of immune cell that plays a role in cell-mediated immunity.

**Option B:** This option is incorrect because plasma cells are not derived from macrophages, which are a type of immune cell that engulfs and digests foreign particles and microorganisms.

**Option C:** This option is incorrect because plasma cells are not derived from dendritic cells, which are a type of immune cell that presents antigens to T cells and helps to activate the adaptive immune response.

**Clinical Pearl / High-Yield Fact**
It's worth noting that plasma cells can produce a wide range of antibodies, including IgA, IgD, IgE, IgG, and IgM. Each of these antibody isotypes has a different function and plays a role in different aspects of the immune response.

**Correct Answer:** B. B lymphocytes (B cells).