**Core Concept**
Type II hypersensitivity is an immune-mediated reaction where antibodies bind to specific antigens on the surface of host cells or tissues, leading to their destruction. This type of hypersensitivity involves the activation of complement and the release of cytotoxic molecules, resulting in cell lysis or tissue damage.

**Why the Correct Answer is Right**
The correct answer is mediated by antibodies, specifically IgG and IgM, which are the primary immunoglobulins responsible for type II hypersensitivity reactions. These antibodies bind to antigens on the surface of cells, marking them for destruction. The Fc region of the antibody interacts with immune effector cells, such as neutrophils and macrophages, which release cytotoxic molecules, including complement, to lyse the target cells. This process is often seen in autoimmune diseases, such as Goodpasture's syndrome, where antibodies target the basement membrane of the lungs and kidneys.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because type I hypersensitivity reactions are mediated by IgE antibodies, which trigger mast cell degranulation and the release of histamine, leading to anaphylaxis.

**Option B:** This option is incorrect because type III hypersensitivity reactions involve the formation of immune complexes, which deposit in tissues and activate the complement system, leading to inflammation and tissue damage.

**Option C:** This option is incorrect because type IV hypersensitivity reactions are cell-mediated, involving T lymphocytes rather than antibodies. These reactions are often seen in contact dermatitis and transplant rejection.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that type II hypersensitivity reactions can be mediated by both IgG and IgM antibodies, and that the Fc region of the antibody plays a crucial role in interacting with immune effector cells.

**Correct Answer: D. Antibodies.