Actually it's the leopard.
The answer has to be choice d
Answer: whether, weather
Explanation: Looking at the Grey sky, Becky wondered WHETHER the WEATHER would ruin the class trip.
Weather and whether although having a similar pronunciation do not perform same function in a sentence.
Weather is used to describe the temperature and precipitation activity at a certain point in time while WHETHER is a word used as a condition between two likely outcomes.
You haven’t given any clues. There’s not a good chance to get this right with the information you’ve given
