Final answer:
Social insurance is the element that best describes insurance written in support of public policy.
Step-by-step explanation:
The element that best describes insurance written in support of public policy is social insurance. Social insurance refers to insurance programs that are established by the government to protect individuals against certain risks or adverse events. These programs are funded by contributions from the general public and provide benefits to those who experience the specified risks. Examples of social insurance programs include Medicare and Medicaid, which offer healthcare coverage to specific groups of people.