The $IUPAC$ name of $CH_2=CH-CH_2-COOH$ is

Given below are two statements:
Statement $I$: $IUPAC$ name of $HO-CH_2-(CH_2)_3-CH_2-COCH_3$ is $7-$hydroxyheptan$-2-$one.
Statement $II$: $2-$oxoheptan$-7-$ol is the correct $IUPAC$ name for above compound.
In the light of the above statements,choose the most appropriate answer from the options given below:

The correct $IUPAC$ name of $H_2C=CH-CH(CH_3)-CH_2-C \equiv CH$ is:

The $IUPAC$ name of the following compound is:

The $IUPAC$ name of $CH_3-CH=CH-C\equiv CH$ is

The $IUPAC$ name for $CH_3-CH=CH-CH_2-CH(NH_2)-CH_2-COOH$ is