Answer:
The order of succession to the presidency in the United States, should the President be unable to fulfill their duties, is as follows:
1. Vice President
2. Speaker of the House of Representatives
3. President pro tempore of the Senate
4. Secretary of State
5. Secretary of the Treasury
6. Secretary of Defense
7. Attorney General
8. Secretary of the Interior
9. Secretary of Agriculture
10. Secretary of Commerce
11. Secretary of Labor
12. Secretary of Health and Human Services
13. Secretary of Housing and Urban Development
14. Secretary of Transportation
15. Secretary of Energy
16. Secretary of Education
17. Secretary of Veterans Affairs
18. Secretary of Homeland Security
This order is established by the Presidential Succession Act, and it ensures that there is a clear line of succession in case of a vacancy in the presidency or if the President is unable to perform their duties. The Vice President is the first in line, followed by various members of the President's Cabinet and congressional leaders in a specific order.