The correct answer is C) 20th amendment.
The 12th amendment deals with the election of the president and vice president. This changed the process to ensure that the president and vice president are voted on as a couple rather than having the person who won the electoral college as the president and the person who finished second as the vice president.
The 17th amendment resulted in US citizens directly electing their Senators rather than the Senators being picked by a states legislature.
The 25th amendment was passed after Kennedy's assassination and deals with the procedures of what should happen in the case that a president dies or becomes unable to serve during their term.
This shows why C is the correct answer.
