According to the Twelfth Amendment, to prevent a tle between a presidential
and vice-presidential candidate, the
electors _.

The correct answer is A cast one vote for president and one for vice president.

Explanation:

The presidential candidate receiving the greatest number of votes—provided that number at least equaled a majority of the electors—was elected president, while the presidential candidate receiving the second-most votes was elected vice president.

In cases where multiple candidates tied for the second-most votes, the Senate would hold a contingent election to select the vice president. The first four presidential elections were conducted under these rules.

(United States Constitution)