Step 1: Concept IUPAC nomenclature requires selecting the longest carbon chain containing the principal functional group (double bond) and numbering it to give the double bond the lowest possible locant.
Step 2: Meaning The parent chain must include the alkene. Substituents like bromine and methyl groups are then identified and numbered based on their position on this parent chain.
Step 3: Analysis The longest chain containing the double bond has 5 carbons (pentene). Numbering starts from the right to give the double bond the lower number (position 2). This places the bromine atom and the methyl group at position 4.
Step 4: Conclusion Combining the locants and names alphabetically (Bromo before Methyl), the name is 4-Bromo-4-methylpent-2-ene.
Final Answer: (B)
