Which of the Following Is the Formula of the Polyatomic $\mathrm { O } _ { 2 } ^ { 2 - }$

Which of the following is the formula of the polyatomic ion peroxide?

A) $\mathrm { O } _ { 2 } ^ { 2 - }$

B) $\mathrm { CN } ^ { - }$

C) $\mathrm { HPO } _ { 4 } ^ { 2 - }$

D) $\mathrm { HPO } _ { 4 } ^ { 2 - }$ .

E) $\mathrm { HPO } _ { 3 } ^ { 2 - }$