Answer:
a. he or she can advise that justice on how to vote on future cases
Step-by-step explanation:
In appointing a judge to the federal supreme court, the president ensures that he will have representation at the largest judicial institution in the country. In this case, the president may advise the individual who has been appointed as a judge to act in accordance with the ideologies and plans that the president has, in a sphere of public power in which he or she has no direct participation.
In this way, the president exercises his power through a powerful and influential figure in the country's legislative branch.