The correct answer is A because Apache uses the %r directive to log the full request line exactly as sent by the client. Apache's official logging documentation explains that the request line includes the method, the requested resource, and the protocol version, which is precisely what investigators need when reviewing suspicious URL-appended input. In practical forensic terms, this field helps analysts compare the attacker's submitted payload with corresponding spikes in application errors or timing anomalies. %{Referer}i records the HTTP Referer header, %h logs the client host, and %u records the authenticated remote user, so none of those captures the full request line. CHFI v11 includes Apache access and error logs, web-application attack investigation, and analysis of log evidence, so recognizing what each directive represents is directly within scope. When the objective is to recover the exact request syntax used in a possible injection or cross-site scripting attempt, the request-line directive is the most valuable field. Therefore, the correct Apache log directive is %r.