I believe the answer is: c. question
The word 'ponder' mean thinking about a certain thing carefully, even if it took a lot of time to do it. This word is often used in a situation when someone trying to find an answer in an unfamiliar situation. Because of this, it think the word 'question' has a similar meaning with ponder.
You are correct - no change is indeed necessary in this sentence, because the pronoun <em>their </em>is the correct pronoun which you should use in the example above.
You cannot use <em>his, </em>because there are more than one brother involved. You cannot use <em>her, </em>because the omelette belongs to both the mother and the brothers. And the third option is also incorrect because of <em>his </em>in the singular form.
“I want to visit Canada” (capital “i”)
It will help you know what mistakes to avoid and what will draw positive attention to the presentation. Ex. Don't chew gum while giving a presentation, it will be seen as unprofessional. Do: Make eye contact with the audience, the audience might be more engaged if they feel like you're having a conversation with them.
C. Not sure where juxtaposition is, but C is the only thing which the passage argues for or suggests.