The structure of Campus module in SAFE medium architecture may be altered. Choose the correct statement.

A.
Both alternatives are allowed.

B.
The functions of the layer 2 switch, can be integrated into the core switch.

C.
If the performance requirements are not too high, the core switch can be replaced by a layer 2 switch and a router.

D.
None of these alternatives are allowed.

Explanation:
If the medium network is small enough, the functionality of the building switches can be rolled into the core switch, and the building switches can be eliminated. If the performance requirements of the internal network are not high, a separate router and Layer 2 switch could be used for the core and distribution instead of the higher-performing Layer 3 switch.
Reference: Safe white papers;page 23
SAFE: Extending the Security Blueprint to Small, Midsize, and Remote-User Networks