An example of this would be not paying attention to the more important things in a situation.
So picture this; Jacob gets in a argument with his mom in public. They're standing at the crosswalk, waiting to cross. Jacob's mom is annoyed by Jacob being on his phone instead of talking to her, so the two start arguing. Jacob's mom wasn't paying attention, and heard the chirp of a nearby crosswalk signal telling their people to walk. She does not look where she is going, walks into traffic, and gets hit. The small decisions were her not paying attention and she decided to pick a fight. The consequence of these built up and she got hit by a car.
The common synonyms are usually unknown, uncertain, unclear, etc.
If you read an unfamiliar word and you don't have a dictionary at your disposal, you could use context clues. From the word itself, they are words within the sentence that help you give context to what the thought means. The context clues to be used here are 'pale yellow woods'. Thus, waning may mean it's malnourished or dying. It's antonym from the given choices is strengthening. So, the answer is C.
