In how many of the following substrates nitrogen is intact with initial substrate after repeative exhaustive methylation followed by Hoffman eliminaton ?

 

In (A) and (C)

Exhaustive methylation: The process of alkylation with methyl groups until all possible methylations have been achieved. In the Hofmann elimination reaction sequence, exhaustive methylation (shown in red) converts an amine to an alkylammonium salt prior to E₂ elimination.