Answer:
B). It must be enacted by law.
Step-by-step explanation:
Public policy is chiefly characterized by its affinity with the laws, regulations, and principles as the prime goal of such policies is to 'reflect the plan or course of action to bring about the desired changes' in order to ensure public welfare which requires to be addressed by the laws.
As per the question, option B best reflects a defining feature of a public policy as in order to bring about a change, transformation, solution to a social problem, or creation of the desired state must address and abide by the laws to ensure its successful and effective execution or reinforcement among the public. Therefore, option B is the correct answer.