Draw the products in each reaction.

a.

b.

c.

d.

Strong bases such as hydroxides and ethoxides favor a mixture of both E2 and ${\text{S}}_{\text{N}}\text{2}$ reactions, while bulky bases like tert-butoxide provide E2 reactions.

Strong nucleophiles like hydroxides and ethoxides generate a mixture of both E2 and ${\mathbf{\text{S}}}_{\mathbf{\text{N}}}\mathbf{\text{2}}$. In comparison, weak nucleophiles yield E1 and ${\mathbf{\text{S}}}_{\mathbf{\text{N}}}\mathbf{\text{1}}$reactions.

As the number of substitutions of the alkyl groups increases, the stability increases due to the +I effect of the alkyl substituents.

So, following all the explanations, the following products are obtained.

Representation of all possible products from reaction a

Representation of all possible products from reaction b

Representation of all possible products from reaction c

Representation of all possible products from reaction d