The following are some statement related to VA group hydrides,

Question

I. Reducing property increases from $NH_3$ to $ BiH_3$

II. Tendency to donate lone pair decreases from $NH_3$ to $BiH_3$

III. Thermal stability of hydrides decreases from $NH_3$ to $BiH_3$

IV. Bond angle of hydrides decreases from $NH_3$ to $BiH_3$

The correct statements are

(a)  I,II,III and IV

(b)  I,III and IV

(c)  I,II and IV

(d) I and IV