I would say D. All of these answers are correct.
Because:
You shouldn't expect perfection; you don't want to get your hopes up, for when something could always potentially go wrong.
Turn negative thoughts into positive ones; You are your biggest critique.
Acquire Speaking experience; Practice is always a good thing.
Education is an important foundation in charge of molding and shaping the minds of our youth without any bias but with pure facts, truths, so then one day they to can make well-informed decisions on there own.