The best reaction sequence to convert 2-methyl-1-bromopropane into 4-methyl-2-bromopentane is

(i) Mg in ether (ii) acetaldehyde (iii) $$\text{H}^+$$, $$\text{H}_2\text{O}$$ (iv) heat (v) HBr, $$\text{H}_2\text{O}_2$$

(i) $$\text{NaC} \equiv \text{CH}$$ in ether (ii) $$\text{H}_2$$, Lindlar catalyst (iii) HBr, no peroxide

(i) alcoholic KOH (ii) $$\text{CH}_3\text{COOOH}$$ (iii) $$\text{H}_2$$/Pt (iv) HBr, heat

(i) $$\text{NaC} \equiv \text{CH}$$ in ether (ii) $$\text{H}_3\text{O}^+ + \text{HgSO}_4$$ (iii) HBr, heat