It would be much better if there was a context representing the idea which has to be determined. But 'whom' actually can pose as an object in the sentence, only when it is <span>objective case.</span>
The answer that best fits the blank above is the word RECALL. When writing an essay, you are writing about a topic and this topic is something that you have deeply understood. You will be talking about it using your own words and therefore, you must remember the whole idea of the topic. With these, you will need the use of RECALL in remembering cues.
