Final answer:
In contractarianism, the final authority on ethics is based on conventions that are agreed upon by society, highlighting mutual agreement of its members over personal views or law alone for determining ethical standards.
Step-by-step explanation:
According to the moral theory of contractarianism, the final authority on ethics is c. conventional.
Contractarianism, a form of moral theory within the realm of normative ethics, posits that moral norms derive their normative force from the idea of contract or mutual agreement. Grounded in the idea of a social contract, it asserts that individuals accept certain moral and political obligations by virtue of being members of a society.
This implies that the final authority on what is considered ethical behavior is not determined in isolation (personal) nor by the law alone but by the conventions and agreements arrived at by the members of that society. Hence, individuals are bound to the moral codes that they have collectively agreed upon within their cultural or societal context.