The answer to your question would be that the sentence that is punctuated correctly is the following one: Zora said, "It will take me forever to learn the Beethoven piece that my teacher assigned today!"
Quotation marks are for when you want to use someone else's words in your writing. If you are quoting a complete sentence, you should start the quote with a capital letter, even if the quote is in the middle of the sentence. That is why the one with the capital letter is the correct answer.
