I believe the correct answer is c
The antonym is D. Reckless because cautious is to be very careful about your thoughts and actions. Reckless is completely insane. Your Welcome:)
Answer:
It signals that while horrors are occurring in the concentration camps, the world continues to function normally.
Explanation:
There is an element of irony, or of contrast here, because life in concentration camps was the complete opposite from the beautiful weather. The author took the time to create the contrast to highlight the horrors occurring in the concentration camps.