Answer:
Twelfth Amendment.
Step-by-step explanation:
It provided the procedure for electing President and Vice President. It replaced the procedure provided in Article II, Section 1, Clause 3 of the United States Constitution. Before that amendment, the Vice President was the second most-voted presidential candidate.
The amendment improves that problem and gave the electoral college the power to cast one vote for President and one vote for Vice President.
I hope this answer helps you.