**Core Concept**
Type-II hypersensitivity reactions involve the binding of antibodies to cell surface antigens, leading to cell destruction through mechanisms such as complement activation, antibody-dependent cellular cytotoxicity (ADCC), or direct cell lysis. This type of reaction is typically mediated by IgG or IgM antibodies.

**Why the Correct Answer is Right**
In a type-II hypersensitivity reaction, the antibodies bind to the target cells, marking them for destruction. The presence of complement and phagocytic cells such as neutrophils and macrophages further contributes to the elimination of the targeted cells. This process is a key component of immune responses against foreign cells, such as red blood cells in autoimmune hemolytic anemia.

**Why Each Wrong Option is Incorrect**
**Option A:** Not a type-II hypersensitivity reaction - Type-I hypersensitivity reactions involve IgE antibodies and the release of histamine from mast cells, leading to allergic responses.
**Option B:** This is a type-II hypersensitivity reaction - An example of a type-II hypersensitivity reaction is autoimmune hemolytic anemia, where antibodies bind to red blood cells and mark them for destruction.
**Option C:** This is a type-II hypersensitivity reaction - The binding of antibodies to platelets in idiopathic thrombocytopenic purpura (ITP) is a type-II hypersensitivity reaction, leading to the destruction of platelets.
**Option D:** Not a type-II hypersensitivity reaction - Type-IV hypersensitivity reactions involve T-cell mediated immune responses, such as contact dermatitis or tuberculin reactions.

**Clinical Pearl / High-Yield Fact**
Type-II hypersensitivity reactions are often associated with autoimmune diseases, such as autoimmune hemolytic anemia, Graves' disease, or Goodpasture's syndrome. These reactions highlight the complex interplay between the immune system and the body's own tissues.

**Correct Answer:** A.