Answer:
b. Being confirmed by the Senate
Explanation:
Regarding the selection process for all federal judges, Article II of the U.S. Constitution states the following:
<em>... and he </em><em>(The President) shall nominate, and by and with the advice and consent of the Senate, shall appoint</em><em> ambassadors, other public ministers and consuls, </em><em>judges</em><em> </em><em>of the Supreme Court</em><em>, and all other officers of the United States, whose appointments are not herein otherwise provided for, and which shall be established by law.</em>
Therefore, in order for a person to become a federal judge, they first have to be appointed by the President (who has to take into account the Senate's advice), and then they have to be confirmed by the Senate. This selection process is a clear example of how the Checks and Balances system work in the U.S., in which each branch of the government has the power to oversee, check and limit the other branches.