Which of the following are methods to implement HA in a web application server environment? (Select two.)

Load balancers distribute incoming client requests across multiple backend web servers, ensuring no single server becomes a bottleneck or single point of failure; if one server fails, traffic is automatically redirected to healthy servers, directly enabling HA.

Reverse proxies sit between clients and backend servers, forwarding requests to one or more servers while abstracting the backend topology; they support HA by routing around failed nodes, caching responses, and enabling seamless failover without client awareness.

While reverse proxies do support HA and are a valid answer in many contexts, the marked correct answers per this question are A and B; however, note that the stated correct answer of B (Application layer firewalls) primarily provides security inspection rather than traffic distribution or failover for HA.

VPN concentrators aggregate encrypted tunnel connections for remote access or site-to-site connectivity and do not provide traffic distribution or failover capabilities for web application server HA.

Routers operate at Layer 3 to forward packets between networks based on IP routing tables and do not perform server health monitoring, session persistence, or traffic load distribution needed for web application HA.