Arrange the following in the increasing order of the properties stated against them.
(a) (i)`NH_(3)` , (ii)`PH_(3)`, (iii)`AsH_(3)` , (iv)`SbH_(3)`-boiling point.
(b)(i)`Bi^(3+)` ,(ii)`Sb^(3+)` , (iii)`As^(3+)`-stability of `+3` oxidation state.
( c)(i)`NH_(3)`, (ii)`PH_(3)` , (iii)`AsH_(3)` , (iv)`SbH_(3)` , (v)`BiH_(3)`-reducing character.

Explanation

Volatile nature: `NH_(3)ltSbH_(3)ltAsH_(3)ltPH_(3)`.