Answer: (4) Rights theorists
Explanation:
According to the question, the observer are taking about the right theorists as the observer are most likely discussing about the actual rights of workers. They deemed that there are various things they cannot do as they do not against as an individual.
As, it is related to the individual rights and they hold the moral rights and they also protect themselves from any type of harmful effects. Therefore, Option (4) is correct as they are related to the particular individual rights.