Assertion:- `H_(3)PO_(4)` is a dibasic compound.
Reason:- The two H-atom are directly attached to P.

Assertion : H_(3)PO_(3) is a diabasic acid. Reason: There are two H atoms directly attached to P.

Assertion : H_(3)PO_(2) is a diabasic acid. Reason: There are two H atoms directly attached to P.

Assertion : Phosphoric acid is a tribasic acid. Reason : Three H atoms are directly attached to P atom.

(A) H_(3)PO_(3) is tribasic acid (R ) Three H atoms are directly attached to P atom in a H_(3)PO_(3) molecule.

Asseration: Both H_(3)PO_(4) and H_(3)PO_(3) posses the same number of hydrogen atoms, but H_(3)PO_(4) os tribasic acid and H_(3)PO_(4) is dibasic. Reason: In oxoacids only those H -atoms are replaceable which are attached to O-atom .

Assertion: Phosphorous acid is a dibasic acid Reason: In phosphorous acid, there are two H-atoms directly attached to phosphorous.

Statement-1 : H_(3)PO_(3) is a dibasic acid and shows reducing character. Statement-2 : H_(3)PO_(3) contains two OH- groups and one hydrogen atom directly attached to P atom.