**Core Concept**
The question tests the understanding of **retention cysts**, which are a type of cyst that forms when a gland or its duct becomes obstructed, leading to the accumulation of secretions. This concept is crucial in **pathology** and **clinical diagnosis**. Retention cysts can occur in various parts of the body, including the skin, ovaries, and pancreas.

**Why the Correct Answer is Right**
Although the specific correct answer is not provided, a retention cyst typically forms due to the blockage of a gland's excretory duct, causing the gland's secretions to accumulate and form a cyst. This can occur in various tissues, including the **ovary**, **pancreas**, or **skin**, leading to different types of retention cysts.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific details of option A, it's challenging to provide a precise explanation for its incorrectness.
**Option B:** Similarly, without knowing what option B entails, its incorrectness cannot be detailed.
**Option C:** This option would be incorrect if it does not accurately describe a condition resulting from the obstruction of a gland or duct.
**Option D:** If option D does not align with the definition or formation mechanism of a retention cyst, it would be an incorrect choice.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that retention cysts are usually **benign** and can often be diagnosed based on their appearance and location. Understanding the distinction between retention cysts and other types of cysts or tumors is crucial for **accurate diagnosis and treatment**.

**Correct Answer:** Correct Answer: D. Retention cyst of the ovary, also known as an ovarian cyst, forms when a gland in the ovary is obstructed.