An intranet connected to the internet is often protected by __________

an-intranet-connected-to-the-internet-is-often-protected-by

An intranet connected to the internet is often protected by __________

A. a DNS

B. a “brick wall”

C. a “fire wall”

D. antivirus

The question was asked in final exam.

My question comes from Digital Multiplexing in portion Multiplexing & Sampling of Bandpass Signal of Analog Communications

Correct answer is A. a DNS

The explanation is: Intranet uses internet technologies, but is insulated from the global internet. An intranet connected to the internet is often protected by DNS.