Ensure that your argument is well prepared (facts, know your audience and what their preference is, etc). Good ways to present are to use emotion or strong facts. Don't exaggerate facts, thiscan lead to downgrades in your presentation grade. Make sure that everyone can understand, so simplify your topic if need be.
Make eye contact with audience. don't have the paper cover your face since it blocks your sound. try to stand still. paraphrase the quotes so they are shorter and easier to understand.
The correct answer is Nominative case.
This is the primary case where pronouns are I, You, he/she/it, we/you/they. In an objective case, the pronouns would be changed into me, him, her, them, us, and similar. Possessive would be if the pronouns became possessive pronouns and would be something like mine, yours, ours, and other similar forms of pronouns.