The correct order of reducing abilities of hydrides of V group elements is

Question

$$\begin {array} {1 1} (1)\;NH_3 < PH_3 < AsH_3 < SbH_3 < B_iH_3 & \quad (2)\;NH_3 > PH_3 > AsH_3 > SbH_3 > B_iH_3 \\ (3)\;NH_3 < PH_3 > AsH_3 > SbH_3 > B_iH_3 & \quad (4)\;SbH_3 > BiH_3 > AsH_3 > NH_3 > PH_3 \end {array}$$