Which of the following compounds will not give `S_(N^(2))` reaction?

Which of the following compounds will give S_(N^(1)) reaction?

Which of the following compounds will give S_(N)1 reaction in polar protic solvent:

Which one of the following compounds will undergo only S_(N)2 reaction-

Which of the following compounds will be most reactive in S_(N)1 reaction ?

Predict the order of reactivity of the following compounds in S_(n^(1)) and S_(N^(2)) reactions : The four isomeric bromobutanes,