What is the central hub called in a Token Ring network?

What is the central hub called in a Token Ring network?

A.
Star

B.
MAU

C.
PBX

D.
MUA

Explanation:
Each computer in a Token Ring network is connected to a Multistation
Access Unit (MAU), which acts as a central hub. The token will go around to each
computer connected to this centralized device in a collapsed ring. The topology, in
this example, is a physical star while the technology works in a logical ring.