Which of the following is NOT one of the first four members of the alcohols series?

The first four members of the alcohol series are characterized as having a molecular formula that follows the general formula CnH2n+1OH, where n represents the number of carbon atoms.

Starting with one carbon atom (methanol, CH3OH), the series progresses as follows:

1. Methanol (1 carbon)
2. Ethanol (2 carbons)
3. Propanol (3 carbons)
4. Butanol (4 carbons)

Each of these corresponds to the first four members of the alcohol series. Hexanol, on the other hand, has six carbon atoms (C6H13OH) and therefore does not belong to the first four members—making it a higher member of the series. This is why hexanol is identified as the correct answer, as it is not one of the first four alcohols.