It's not a quiz to just test your memory. First, it's about style. Does the style seem contemporary or antiquated? What details give you that impression? Word choice, syntax, names? And second, does the content give you clues as to the author? Finally, does the first line do for the story what you think is best? First lines are important to engage the reader with the question: What comes next? How would you change what's on the page?
If you don’t remember (or have never read) the book the quote is taken from, ask: what year the work might have been published? does the content and style give you a clue to the author? and is the vocabulary distinctive? Good luck!