Increasing strength towards nucleophilic attack?

Assertion (A) Benzaldehyde is less reactive in comparison to ethonal towards nucleophilic attack. Reason (R ) All the carbon atoms of benzaldehyde are sp^(2) - hybridised.

The correct order of the following compounds showing increasing tendency towards nucleophilic substitution reaction is :

Arrange the given alkylhalides in the increasing reactivity towards Nucleophilic substitution reactions

Least reactive towards nucleophilic additon is

Which one of the following is most reactive towards electrophilic attack?