First we need to identify the longest carbon chain. Once we do that, the actual structure should read CH₃—CH₂—CH(CH₃)—CH₂—Br. –Br, the functional halide group is attached to the first carbon atom, so we start the numbering from that position. The methyl group branch is bond to the second carbon atom in the chain. The number of carbons in the unbranched parent chain are four, thus giving the name butane. The molecule is named 1-Bromo-2-methylbutane. Option (ii) is correct.