You are working as a technician at Certkiller .com. A user wishes to buy a new keyboard that is
connected through USB, but he says that he already has 2 USB devices and is concerned that he
won’t be able to connect another one. How many USB devices can be connected to a system at
the same time? What will you tell the user?

A.
7

B.
15

C.
127

D.
126

Explanation:
A USB system has an asymmetric design, consisting of a host multitude of downstream USB
ports, and multiple peripheral devices connected in a tiered-star topology. Additional USB hubs
may be included in the tiers, allowing branching into a tree structure, subject to a limit of 5 levels of
tiers per controller. Up to 127 devices, including the hub devices, may be connected to a single
host controller.