i hate to tell you but communism has nothing to do with monarchs, lords and nobles. If unsure with a question like this, probably the best thing to do is a quick search on all your possible answers, this will probably give you the answer you are looking for quicker than waiting for somebody to reply to a post.
You need to learn to go back into your textbook or study materials to find these answers or learn to conduct simple searches. Enter each of the terms you listed until you find a definition that matches.
http://www.answers.com
http://en.wikipedia.org/wiki/Main_Page
http://www.google.com
The correct answer is D) feudalism. Feudalism was a social and economic system that emerged in the Middle Ages, where monarchs or lords granted land to nobles in exchange for their loyalty, military service, and other duties.