Here is the full question:
 Which of the following is NOT a Congressional power?
Lay and collect taxes 
Raise and support an army 
 Declare war 
 Nominate federal judges
Answer:
 Nominate federal judges
Step-by-step explanation:
Congress belong to the legislative branch.
The nomination of the federal judges belong to the president, which is a part of the executive branch.
The Congress only has the power to 'Confirm' the ones nominated by the president. Members of congress will conduct background check to the nominee and voted among themselves to accept or dismiss the nomination.