Which idea is included in the concept of natural law?
ethical principles can be discovered through reason.
philosopher-kings tell citizens what ethical principles are.
governments and people cannot exist without each other.
none of these ideas are included.

Ethical principles can be discovered through reason which is included in the concept of natural law. The reason is that the basic facets of the natural law are the law and mortality which are interlinked. Ethics is like the instructing of logic for the things through agreement. Truthfulness, confidentiality, autonomy and informed consent are the principles of ethics which are considered.  

answer; i believe its a