**Core Concept**
The dura mater is the outermost meningeal layer enveloping the brain and spinal cord. It is composed of two layers: the endosteal dura and the perosteal dura, which are separated by the dural venous sinuses.

**Why the Correct Answer is Right**
The dura mater is a fibrous, vascular layer that plays a crucial role in the protection and support of the central nervous system. It is highly innervated, which allows it to respond to various stimuli, including pain and inflammation. The dural venous sinuses, located between the two layers of the dura, are responsible for draining blood from the brain and play a critical role in the venous circulation of the central nervous system.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because the dura mater is indeed a protective barrier against infection and injury, and it plays a crucial role in the production and circulation of cerebrospinal fluid.
**Option B:** Incorrect because the dura mater is indeed a highly vascular layer, and it contains numerous blood vessels, including the dural venous sinuses.
**Option C:** Incorrect because the dura mater is indeed a fibrous layer, composed of collagen and elastin fibers, which provide it with strength and elasticity.

**Clinical Pearl / High-Yield Fact**
The dura mater is a highly innervated layer, and its stimulation can lead to pain and inflammation. This is why procedures involving the dura, such as dural puncture or dural tear, can be associated with significant pain and discomfort.

**Correct Answer:** D.