Answer:
Water
Explanation:
water molecule contains one oxygen covalently bound to two hydrogen atoms with no carbon present.
D because if the species was to be removed from an ecosystem, everything that needed that species as food, or the species ould have to adapt to the foods available in the new ecosystem they live in. Hope I helped, and let me know if you are still not 100% sure about the answer, and I'll try to clarify what I said.
Just draw a dot and cross diagram showing covalent bonding between sodium and chlorine.