Morpheme is the smallest meaningful unit of language structure.
affix is something placed at the beginning or end of something that changes the meaning.
suffix is placed after the word to change the meaning.
prefix is placed at the beginning of the word to change the meaning.
You don't list any choices, but colloquialisms are used in informal speech. Hope it helps.
I believe it will be a cause and effect type of essay.
I hope this helps