The correct answer is Content filtering.

A web proxy sits between users and the internet so it can inspect web requests and responses and then enforce policy. This inspection allows the proxy to block categories of sites, remove or alter content, and log activity for auditing which is why Content filtering is the primary security capability in this scenario.

URL blocking is not the best answer because it describes only a specific action that falls under the broader practice of content filtering. A proxy can and often does block URLs but the full capability includes category filtering, pattern matching, and policy enforcement which is captured by Content filtering.

Cloud Armor is a named cloud service that provides DDoS protection and web application firewall features for cloud applications. It is not the general proxy function of managing employee browsing and recording requests.

Virus detection is generally performed by endpoint AV or dedicated scanning gateways. Proxies focus on inspecting and filtering web content and logging requests and they do not primarily act as full antivirus engines.

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