I'm assuming you mean the molecular compound

and it's name is Hydronium. Hope this helps :)
I'd go with A. can interact to influence a trait, such as eye color
Answer:
a. on the outer surface of the epiphyses.
Explanation:
Articular cartilage of a long bone is found on the outer surface of the epiphyses.
Covalent Bonds hold together atoms within a molecule