The major product formed in the following reaction is

Choose the correct answer from the options given below :

Compound 'B' is

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

Assertion A : $$\left[\mathrm{CoCl}\left(\mathrm{NH}_{3}\right)_{5}\right]^{2+}$$ absorbs at lower wavelength of light with respect to $$\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5}\left(\mathrm{H}_{2} \mathrm{O}\right)\right]^{3+}$$

Reason R : It is because the wavelength of the light absorbed depends on the oxidation state of the metal ion.

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

If $$\mathrm{Ni}^{2+}$$ is replaced by $$\mathrm{Pt}^{2+}$$ in the complex $$\left[\mathrm{NiCl}_{2} \mathrm{Br}_{2}\right]^{2-}$$, which of the following properties are expected to get changed ?

A. Geometry

B. Geometrical isomerism

C. Optical isomerism

D. Magnetic properties