Answer:
The answer: the Senate Judiciary Committee.
Step-by-step explanation:
The power of the President to appoint a new Supreme Court Justice is under Article II, Section 2, Clause 2 of the Constitution of the United States of America. This is confirmed by the Senate Judiciary Committee. There are actually no particular set of requirements for the nominated person, it only depends on the will of the President.
The Senate Judiciary Committee supervises the Department of Justice, thus they try to check the nominated individuals who will provide service to Justice. They will hold hearings whether they will approve or reject such nominations. This is the power that the Senate has.