The step you must complete bbefore writing a media assessment essay is finding strong supporting details to prove your point. Option A is correct.
An assessment essay deals with a critical analysis of something or someone else, (in this articular case, the analysis of media).
When writing and assessment essay, you have to take into account the purpose of the piece of writing, the counterarguments, the information known of the topic to be addressed in the paper, and a good organization of the ideas throught out it.