Cisco Web Security Appliance, commonly referred to as WSA, is the Cisco platform associated with web proxy functions, web filtering, malware defense for web traffic, and proxy caching behavior. Proxy caching improves web performance by storing previously retrieved web objects so repeated requests can be served more efficiently. Firepower and FireSIGHT relate to firewall and threat defense visibility, while ASA is Cisco ' s Adaptive Security Appliance firewall platform. They are not the web proxy caching answer in this context. Cisco CCNA 200-301 v1.1 expects candidates to recognize basic security device roles: firewalls inspect and enforce traffic policy, WSA protects and optimizes web access, and AAA systems handle identity and authorization. The phrasing is direct: improve web traffic performance by proxy caching. That is a web security/proxy function, so WSA is the best match. The correct answer is A.