Final answer:
In the IUPAC system, alcohols are named by changing the ending of the parent alkane name to -ol. Aldehydes have the ending -al, and ketones have the ending -one. The correct option is 1) alcohol.
Step-by-step explanation:
In the International Union of Pure and Applied Chemistry (IUPAC) system, alcohols are named by changing the ending of the parent alkane name to -ol. For example, if the parent alkane is ethane, the alcohol would be called ethanol.
Similarly, aldehydes are named by dropping the -e from the alkane name and adding the ending -al, such as formaldehyde or acetaldehyde. Ketones are named by dropping the -e from the alkane name and adding the ending -one, like acetone or butanone.