Consider the following reaction,where:
$(A)$ The change in the functional group and
$(B)$ The corresponding change in the hybridization from the starting material to the final product are:
$CH_3-C \equiv N \xrightarrow[(ii) \ HI + \text{Red } P]{(i) \ SnCl_2, HCl / H_3O^{+}}$

• A
  $A: -CN$ $\rightarrow -CH_2OH \quad (sp^2$ $\rightarrow sp^3)$
• B
  $A: -CN$ $\rightarrow -CONH_2 \quad (sp$ $\rightarrow sp^2)$
• C
  $A: -CN$ $\rightarrow -CH_2NH_2 \quad (sp$ $\rightarrow sp^3)$
• D
  $A: -CN$ $\rightarrow -CH_3 \quad (sp$ $\rightarrow sp^3)$