Which of the following devices is BEST suited to protect an HTTP-based application that is susceptible to
injection attacks?

A.
Protocol filter

B.
Load balancer

C.
NIDS

D.
Layer 7 firewall

Explanation:
An application-level gateway firewall filters traffic based on user access, group membership, the application or
service used, or even the type of resources being transmitted. This type of firewall operates at the Application
layer (Layer 7) of the OSI model.