Which expression matches requests where the host header equals www.example.com?

• A. HTTP.REQ.HOSTNAME.EQ("www.example.com")
• B. HTTP.REQ.HOSTNAME.("example.com")
• C. HTTP.RES.HOSTNAME.CONTAINS("www.example.com")
• D. HTTP.RES.HOSTNAME.EQ("www.example.com")

Answer: (A)

To match the host header from the incoming HTTP request, you inspect the request attributes, not the response. Use the request hostname and compare it for exact equality. So the expression HTTP.REQ.HOSTNAME.EQ("www.example.com") is correct because it checks that the host in the client’s request is exactly www.example.com.

The other options don’t fit: one misses the operator after the hostname, making it invalid syntax. The other two reference the server’s response (HTTP.RES) instead of the client request, so they wouldn’t match the desired condition of the incoming host header, regardless of the operator used.