How many stereoisomers are possible for the following molecule?

 

The number of optically active isomers possible for:

The$\mathrm{R}/\mathrm{S}$ configuration of these compounds are respectively:

Chiral centres present in the given structures will be:

(i) 

(ii) 

Which of the following molecules is chiral?

The chiral molecules are:

$\left(1\right)$ 

$\left(2\right)$ 

$\left(3\right)$