Which of the following compounds is achiral?

How many different stereoisomers are possible for the following compound?
$Cl-CH=CH-CH(Cl)-CH=CH-Cl$

Total number of stereo-isomers possible for the following compound is:
$1,2$-disubstituted cyclohexane with a $-\text{CH}_2\text{OH}$ group at position $1$ and a $-\text{CH}=\text{CH}-\text{CH}=\text{CH}-\text{CH}_2\text{CH}_3$ group at position $2$.

Which of the following compounds is chiral?

Match the following pairs in Column-$I$ with their respective isomer types in Column-$II$.

Column-$I$	Column-$II$
$A$. Acetaldehyde,vinyl alcohol	$1$. Enantiomers
$B$. Eclipsed and staggered ethane	$2$. Tautomers
$C$. $(+)$$2$-butanol,$(-)$$2$-butanol	$3$. Chain isomers
$D$. Methyl-$n$-propylamine and diethylamine	$4$. Conformational isomers
	$5$. Metamers

The maximum number of isomers that can result from monobromination of $2-$methyl$-2-$pentene with $N$-bromosuccinimide in boiling $CCl_4$ is