Formulae for Nessler's reagent is :

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: can be easily reduced using $\mathrm{Zn}-\mathrm{Hg} / \mathrm{HCl}$ to

Reason $\mathrm{R}: \mathrm{Zn}-\mathrm{Hg} / \mathrm{HCl}$ is used to reduce carbonyl group to $-\mathrm{CH}_{2}-$ group.

In the light of the above statements, choose the correct answer from the options given below:

The most stable carbocation for the following is:

Match List I with List II:

List I (Complexes)		List II (Hybridisation)
A.	$\left[\mathrm{Ni}(\mathrm{CO})_{4}\right]$	I.	$\mathrm{sp}^{3}$
B.	$\left[\mathrm{Cu}\left(\mathrm{NH}_{3}\right)_{4}\right]^{2+}$	II.	dsp$^{2}$
C.	$\left[\mathrm{Fe}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}$	III.	$\mathrm{sp}^{3}\mathrm{d}^{2}$
D.	$\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}$	IV.	$\mathrm{d}^{2} \mathrm{sp}^{3}$