Answer:
c) provide fault tolerance.
Step-by-step explanation:
Fault tolerance means the ability of a computer or network to continue working without any interruption when any of its components fail. Fault tolerant systems use backup components that takes place of the failed components so that there is no loss of service. In cases of failure the system can continue at a reduces level instead of failing completely. SQL database is not fault tolerant so it willl not function in case of interruption or system failure.