Lewis dot structures of carbonate, nitrate and phosphate anions

According to the Lewis dot structure, which of the following anions has more than 4 bond pairs around the central atom?

1) carbonate anion
2) nitrate anion
3) phosphate anion
4) none of these

What I can understand is that the carbonate and nitrate anions have exactly 4 bonds around the central atom, which negative formal charges on the oxygens as needed.

However, the phosphate anion has 5 bonds, it has a double bond with one of the oxygens, and 3 bonds with 3 other oxygens which have negative formal charges. But the answer is given to be 4). Why is that so?

• Because outer $d$ orbitals are obsolete, maybe? – Oscar Lanzi Aug 14 at 10:05