Which statement best describes the dura mater?

• A. Outer layer of meninges, tough, fibrous, double layered
• B. Inner layer of meninges, delicate
• C. Part of brain tissue
• D. Membrane surrounding spinal nerves

Answer: (A)

Dura mater is the outermost protective covering of the brain and spinal cord, and it is a tough, fibrous membrane. In the cranial cavity it has two layers—an outer periosteal layer and an inner meningeal layer—so it’s described as double layered. This combination of being the outermost layer and having a strong, fibrous structure is what makes the statement correct. The other options mischaracterize its position or nature: it isn’t the inner, delicate layer (that’s the arachnoid/pia), it isn’t brain tissue, and while it does cover the spinal cord and nerve roots, describing it as a membrane surrounding spinal nerves misses the standard description of dura as the outer protective meningeal layer.