The correct statement about the compounds $A$ and $B$ is:

The starting material is propene $(CH_3-CH=CH_2)$. The reaction with $H_3O^+$ (acid-catalyzed hydration) follows Markovnikov's rule to give $A$ (propan$-2-$ol,$CH_3-CH(OH)-CH_3$). The reaction with $(i) BH_3/THF$ followed by $(ii) H_2O_2/OH^-$ (hydroboration-oxidation) follows anti-Markovnikov's rule to give $B$ (propan$-1-$ol,$CH_3-CH_2-CH_2OH$). What is the relationship between products $A$ and $B$?

The number of structural isomers possible for the molecular formula $C_4H_8F_2$ are

Minimum number of carbon atoms required for a compound to show positional isomerism?

The number of isomers of $C_5H_{12}$ is:

Which of the following pairs represents metamers?