Which of the following statements are correct about the mechanism of this reaction?
(i) A carbocation will be formed as an intermediate in the reaction.
(ii) will attach the substrate (b) from one side and will leave it simultaneously from other side.
(iii) An unstable intermediate will be formed in which and will be attached by weak bonds.
(iv) Reaction proceeds through mechanism.
(i), (iv) are correct. As the given reaction is a tertiary halide, therefore mechanism will be present and as an intermediate, carbocation is formed.