**Core Concept**
The suboccipital triangle is an anatomical region in the neck, bounded by specific muscles. The **suboccipital region** contains key structures, including the suboccipital triangle, which is formed by muscles that play a crucial role in neck movements.

**Why the Correct Answer is Right**
The suboccipital triangle is classically described as being bounded by three muscles: the **rectus capitis posterior major**, the **obliquus capitis inferior**, and the **obliquus capitis superior**. These muscles are involved in the rotation and extension of the head.

**Why Each Wrong Option is Incorrect**
**Option A:** This would be incorrect if it named one of the muscles actually forming the triangle.
**Option B:** Similarly, this would be wrong if it listed another muscle that contributes to the boundary of the suboccipital triangle.
**Option C:** This option is incorrect if it mentions a muscle that is part of the triangle's boundary.

**Clinical Pearl / High-Yield Fact**
The suboccipital triangle is clinically significant because it contains the **vertebral artery** and the **suboccipital nerve**, which are vulnerable to injury in this region.

**Correct Answer: D.**