Explanation:

- Option 1: People working for someone else and are paid wages for their productive activities can be termed hired workers.

- Option 2: Regular salaried workers also fall into the category of hired workers, as they are employed by someone else for a salary.

- Option 3: Those with strong bargaining power who can form trade unions are still hired workers, as they work for others in exchange for wages or salary.

All the above options describe people who work for others and receive compensation, making them hired workers.

Correct Answer: All of the above