Each nominated elector selected pursuant to this article shall, at the time of his nomination and until the conclusion of the day electors cast their votes in the Electoral College, be a citizen of the United States and a legal resident of the Commonwealth, and shall subscribe to an oath, which shall be notarized, that he is, in fact, a citizen of the United States and a legal resident of the Commonwealth, and that he will, if elected, cast his ballot in the Electoral College for the candidates for President and Vice President of the United States as set forth in subsection A or B of § 24.2-241 or pursuant to § 24.2-242, as applicable, or as such political party or group of qualified voters may direct in the event of the death, withdrawal, or disqualification of a candidate of that party or group. The State Board shall also be furnished, if it requests, with satisfactory evidence that any individual undertaking to act as an elector under this chapter is, in fact, qualified and duly and properly authorized to do so.