Some descendants of former royal families are active in:

The correct answer is: d) All of the above

Some descendants of former royal families are active in politics, business, and cultural preservation.

• Politics: Some descendants of former royal families are involved in politics. For example, Prince Charles, the heir apparent to the British throne, is a member of the Conservative Party and has spoken out on a number of political issues.
• Business: Some descendants of former royal families are involved in business. For example, Prince Andrew, the Duke of York, is a former British trade envoy and has worked for a number of companies.
• Cultural preservation: Some descendants of former royal families are involved in cultural preservation. For example, Princess Märtha Louise of Norway is a patron of a number of cultural organizations and has worked to promote Norwegian culture.

It is important to note that not all descendants of former royal families are active in politics, business, or cultural preservation. Some choose to live private lives away from the public eye.