301B Question #58: Real Exam Question with Answer & Explanation

An LTM Specialist needs to rewrite text within an HTML response from a web server. A client is sending the following HTTP request: GET / HTTP/1.1 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/20100101 Firefox/16.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8 Accept- Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Cache-Control: no-cache Connection: keep-alive COOKIE: somecookie=1 HTTP/1.1 200 OK Server: Apache/2.2.15 (Unix) Last-Modified: Wed, 12 Aug 2009 00:00:30 GMT Content-Length: 3063 Content-Type: text/html; charset=UTF-8 Vary: Accept-Encoding Content-Encoding: gzip Connection: Keep-Alive Although a stream profile has been added to the virtual server, the content within the HTTP response is NOT being matched, and therefore NOT modified. Which header is contributing to the issue?