English morphological rules detail how words relate to other words. Thus, my best assumption would be because BOLDEST is an adjective whereas BOLDLY is an adverb.
I think that it is mistake. Because if something is daunting, it is a challenge. If you regret something, it is a mistake.
Answer:
a rattle
Explanation:
it is a percussion instrument
C I’m pretty sure it’s 5 because it kind of like a triangular prism