All of the following are considered factors of production except a vacant piece of land that has never been used.

an antique sewing machine that Jill still uses to alter clothes.

Randy, who has worked as a mechanic for twenty years.

All of the above are factors of production.

Since a vacant piece of land can be used to produce goods and services, it is a factor of production.

Since the antique sewing machine is used to produce clothing, it is a factor of production.

Since Randy is using his labor as a mechanic, his time and effort are factors of production.

This means that all of the above are factors of production.