I'd say the correct answer is B, because 'in the desert is part of the subject/noun 'canyon', and modifies it, that is, refers to it, describes it in more detail.
Answer:
This all depends on context, but in general:
Neutral: Generally having a middle ground opinion rather than being on an extreme side.
Positive: Usually refers to one's attitude, optimism. Can also mean certainty.
Negative: Not positive, could be referring to pessimism or seeing the bad side of things.
A pen
Food
Scissors
Book
Headphones
Phone case
