The correct options are
A H3PO4>H3PO3>H3PO2 (reducing character)
D SbH3>NH3>AsH3>PH3 (reducing character)
(A) In H3PO2, the two H atoms are bonded directly to P atom & in H3PO3, the one H atom is bonded directly to P atom, which imparts reducing character to the acid, whereas in H3PO4, there is no H atom bonded directly to P atom.
Correct order is H3PO2>H3PO3>H3PO4
(B) The oxidation state of nitrogen atom is +1 < +2 < +3 < +5.
(C) Down the group the availability of lone pair of electrons decreases as they are present in more concentrated s-orbital.
(D) As down the group bond energy decreases, the removal of H becomes easier. So, the correct order is SbH3>AsH3>PH3>NH3.