I'm trying to learn spanish Myself, I have a worksheet here with an answer key. I was wondering if anyone who knows spanish could tell me why the answer to that question is that answer. if that makes sense. Please help me understand and learn!
I already Posted this once but it came as that people needed to download it, here it is where you don't have to.

For this question, it will be important to use the words "mejor" (better), "lo mejor" (the best), and "lo peor" (the worst). while "mejor" is comparative (you are comparing one thing to something else), "lo mejor" and "lo peor" are superlative (there is nothing else better or worse than what these words are describing - there is no comparison).  you could say something like: la música rap es mejor que la música clásica - que es lo peor - pero la música rock es lo mejor de todas las formas de la música (rap music is better than classical music - which is the worst - but rock music is the best out of all the forms of music).

El saco  de dormir  is the anwser