Firewalls are used to protect against

[ A ]    Phishing
[ B ]    Vishing
[ C ]    Unauthorized Attacks right
[ D ]    Data Driven Attacks
[ E ]    External resources
Answer : Option C
Explanation :
A firewall is a system designed to prevent unauthorised access to or from a private computer network. It acts as a barrier between a trusted network and an untrusted network. A firewall controls access to the resources of a network through a positive control model.