From the common name of the given compound, we can deduce there are two –C₂H₅ groups, one –Br group bound to a CH₄ molecule. Bromomethane would appear as CH₃—Br. For diethylbromomethane, two ethyl groups can be substituted for the hydrogens in the methyl molecule, forming (C₂H₅)CH(C₂H₅)Br. To provide an IUPAC name, we need to identify the longest parent chain. CH₃—CH₂—CH(Br)—CH₂—CH₃ is identified as the parent chain, and the –Br group from either side is attached to the third carbon atom. The number of carbons in the parent chain are five, so the compound is called 3-bromopentane. The correct answer is (ii).