The major product for the following reaction is:

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Order of acidic nature of the following compounds is A > B > C.

Reason R : Fluoro is a stronger electron withdrawing group than Chloro group.

In the light of the above statements, choose the correct answer from the options given below:

2-Methyl propyl bromide reacts with $$\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{O}^{-}$$ and gives 'A' whereas on reaction with $$\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$$ it gives 'B'. The mechanism followed in these reactions and the products 'A' and 'B' respectively are :