Which of the following performance benefits would multiple domain controllers BEST provide?

A.
Fault tolerance

B.
Caching engine

C.
Proxy server

D.
Quality of service

Explanation:
Fault-tolerant design is a design that enables a system to continue its intended operation, possibly
at a reduced level, rather than failing completely, when some part of the system fails. The term is
most commonly used to describe computer-based systems designed to continue more or less fully
operational with, perhaps, a reduction in throughput or an increase in response time in the event of
some partial failure