Answer:
It would be A.
Step-by-step explanation:
A is a possible answer because it has 4 oxygens, 3 hydrogens, and one phosphorous atom.
B is also a possible answer because it has 4 oxygens, 3 hydrogens, and one phosphorous atom.
C has only 3 Oxygens and 2 hydrogens but we need 4 oxygens and 3 hydrogens so we can rule this one out.
D has 3 hydrogens but only 3 oxygens whereas we need 4 so we can rule this one out as well.
The answer is A because Oxygen atoms have 6 valence electrons and the correct bonding is shown in A.
In B, there are only 5 electrons shown in the bonds so it isn't correct.
Hope this helps!