Which of the following is not a functional isomer of the others?

What is structural isomerism? Give two examples of chain isomerism in alkanes. Or,explain the isomerism of alkanes having more than three carbon atoms using two examples.

Which of the following will have one of the stereoisomers as a meso compound?

Tautomerism is exhibited by:

Identify the pairs of compounds which are functional group isomers.
$I$. $CH_3-CH_2-CH_2-CH_2-OH$
$II$. $CH_3-CH_2-CH(OH)-CH_3$
$III$. $(CH_3)_3C-OH$
$IV$. $CH_3-CH(CH_3)-CH_2-OH$
$V$. $CH_3-CH_2-O-CH_2-CH_3$
$VI$. $CH_3-O-CH_2-CH_2-CH_3$
$VII$. $CH_3-O-CH(CH_3)_2$

Identify the correct statements from the following. Choose the correct answer from the options given below.
$A$. Pentan$-3-$one and Pentan$-2-$one are metamers.
$B$. Butanenitrile and Butaneisonitrile are functional isomers.
$C$. Butan$-1-$ol and Butan$-2-$ol are position isomers.
$D$. Butan$-1-$amine and $N$-methylpropan$-1-$amine are homologous.