To run for Congress, one of the constitutional requirements is to be a U.S. citizen. Additionally, for the House of Representatives, you must be at least 25 years old, and for the Senate, you must be at least 30 years old. Therefore, the correct responses include:
- U.S. citizen
- at least 25 years old (for the House)
- at least 30 years old (for the Senate)
The option "U.S. permanent resident" is not a constitutional requirement to run for Congress.