Question

question 27
which layer of the meninges forms the tough and fibrous outer sac?
a dura mater
b pia mater
c subdural layer
d arachnoid layer

Explanation:

The meninges have three layers. The dura mater is the outermost layer, tough and fibrous. The pia mater is the innermost, delicate. The subdural layer is a potential space, not a true layer. The arachnoid is the middle layer.

Answer:

A. dura mater