Assuming the selections were:
- conference committee
- special or select committee
- joint committee
- committee of the whole
The answer is: special or select committee (2).
Select committees of the United States Congress are usually the result of a resolution outlining their duties and powers on a particular matter. They expire once their designated work is done. Although their purpose is mostly investigative, some of them can draft legislation.
Special congressional committees are a type of select committees. Among them are the Senate Special Committee on Aging or the House Select Committee on the Climate Crisis.