This is a personal question
It's supposed to be Our neighbors are across the street.
Antonyms are opposite in meaning to another. Some examples are - (good - bad) (agree - disagree) (honest - dishonest) (hot-cold) it’s just any words that are complete opposite from each other and it can be more then one word. If a question were to ask what are antonyms of hot you could say cold, freezing, cool, arctic, frigid, etc
The answer is D. Teachers who care about students are some of the greatest people in the world. That's the sentence that stands out and also makes sense.
