**Core Concept**
Rh incompatibility occurs when there is an immune response to Rh-positive blood in an Rh-negative individual, often due to exposure during pregnancy, childbirth, or blood transfusion. This reaction can lead to the production of antibodies against Rh-positive blood, which can cause hemolysis of Rh-positive red blood cells.

**Why the Correct Answer is Right**
The Rh blood group system is a complex antigen complex that involves multiple proteins, including RhD, RhCE, and others. Rh incompatibility arises when an Rh-negative individual is exposed to Rh-positive blood, triggering an immune response and the production of anti-Rh antibodies. This can lead to hemolysis of Rh-positive red blood cells, particularly in subsequent pregnancies or transfusions. The RhD protein is the primary antigen responsible for Rh incompatibility, and its presence or absence determines an individual's Rh status.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the immune response underlying Rh incompatibility.
**Option B:** This option is incorrect because it is too broad and does not specifically address the Rh blood group system.
**Option C:** This option is incorrect because it is a false statement, as Rh incompatibility is not solely related to blood transfusions.

**Clinical Pearl / High-Yield Fact**
Rh incompatibility can be prevented with Rh immunoglobulin (RhIg) administration to Rh-negative women during pregnancy and after childbirth, reducing the risk of hemolysis.

**Correct Answer:** D.