Correct IUPAC Naming of Haloalkanes

Steps:

• Identify the longest carbon chain containing the halogen: butane (4 carbons).
• Number the chain to give the lowest number to the carbon with the Br substituent.
• Name the substituent (bromo) with its position, then the chain (butane); add alkyl branches if present.
• Ensure the name follows IUPAC rules: no redundant numbers or missing locants.

Why A is correct:

• Option A (assuming 2-bromo-3-methylbutane) uses the lowest locant for Br (2) on the butane chain with methyl at 3, per IUPAC priority rules.

Why the others are wrong:

• B: "3-2-bromo-methylbutane" uses invalid dual numbering and unclear structure.
• C: "2-bromo-methylbutane" omits methyl position, violating locant requirements.
• D: "bromo-methylbutane" lacks any position numbers, making it incomplete.

Not enough information for full structure, but A fits standard naming.

Final answer: A