The higher homologue of dimethyl amine has the structure 

$\mathrm{A}.$ ${\left({\mathrm{CH}}_3\right)}_3\mathrm{C}—\mathrm{OH}$

$\mathrm{B}.$ ${\left({\mathrm{CH}}_3\right)}_3\mathrm{C}—{\mathrm{NH}}_2$

Which of the two is the correct statement with respect to the above structures?

The correct IUPAC name of the following compound is:

Which of the statement is correct regarding the above compound?

Identify the total number of different functional groups in the above compound.