The correct answer is cyanate.
The polyatomic ion with the formula CN⁻ is called cyanate. A polyatomic ion has two or more atoms bonded together.
CN⁻ contains the cyano functional group wherein a carbon atom forms a triple-bond to a nitrogen atom. CN⁻ is a polyatomic anion that is present in inorganic compounds.
Answer:
Cynaide and hydrogen phosphate on edg and NH4Cl