Please refer to the following line from a content engine transaction log. 1012429341.115 100 172.16.100.152 TCP_REFRESH_MISS/304 1100 GET http://www.cisco.com/images/homepage/news.gif – DIRECT/www.cisco.com Whats does the 304 mean in this log?

A.
The complete content was retrieved from the origin server.

B.
The complete content was served out of the cache.

C.
An If-modified-since request was sent from the client and the complete content was sent back to the client.

D.
An If-modified-since request was sent from the client and a not modified response code was sent back to the client.

E.
304 bytes of data was sent back to the client.