Which of the following is isomeric with methyl vinyl ether?

The molecules represented by the two structures shown in the image are:

Which of the following types of isomerism is shown by pentanone?

Which of the following will not lose asymmetry on reduction with $LiAlH_4$?

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

Which of the given statement(s) about $N$, $O$, $P$ and $Q$ with respect to $M$ is (are) correct?
$(A)$ $M$ and $N$ are non-mirror image stereoisomers
$(B)$ $M$ and $O$ are identical
$(C)$ $M$ and $P$ are enantiomers
$(D)$ $M$ and $Q$ are identical