Naming the alcohol by identifying the longest chain and substituents

Steps:

• Identify the longest carbon chain containing the OH group: pentane (5 carbons).
• Number the chain to give the OH the lowest number: OH on carbon 2.
• Identify substituents: two methyl groups on carbon 3.
• Combine: 3,3-dimethylpentan-2-ol.

Why C is correct:

• Follows IUPAC rules for alcohols: longest chain includes OH at lowest position, with geminal dimethyl at C3.

Why the others are wrong:

• A: Wrong chain length and OH position; butane implies 4 carbons, not matching the structure.
• B: Incorrect numbering and chain; ethyl substituent misidentifies branches.
• D: Uses functional class name instead of substitutive (IUPAC prefers -ol suffix).

Final answer: C