Only one of the following amines will lose its nitrogen atom as trimethyl amine by repeated Hofmann elimination reactions:

Only one the following amines will lose its nitrogen atom as trimehyl amine by repeated Hofmann elimination reactions:

The nitrogan atom in each of the following tertiary amines may be removed as trimethyl amine by repeated Hoffmann elimination. Which of the following amines requires the greater number of Hofmann sequence to accomplish this?

Which of the following compounds is isomeric with trimethyl amine?