Answer:
The person is c) staff at congressional support agencies.
Step-by-step explanation:
The personnel for this type of work is the legislative staff whose responsibility is to oversee legislation matters. The role is include monitoring of pending legislation, conducting research and providing necessary recommendations on certain issues. The legislative staff deals with legislative analysis in specific areas of expertise such as tax, revenue, environmental matters, health issues, etc.
In the United States, Senators and representatives are assigned legislative assistants to work closely with them in dealing with specific legislative matters or matters which is an assistant is knowledgeable with.