If either of the candidates of a Governor and Lieutenant Governor unit dies, withdraws the candidacy, or becomes disqualified for any reason prior to the deadline for filing a certificate of candidacy for a primary election under § 5-303 of this title, the remaining candidate may: designate a successor candidate who shall file a certificate of candidacy before the later of: the deadline specified under § 5-303 of this title; or the fifth day following the death, withdrawal, or disqualification of the former candidate; withdraw under Subtitle 5 of this title; or after withdrawing under paragraph (2) of this subsection, form a successor unit for the candidacy for the offices of Governor and Lieutenant Governor by filing a certificate of candidacy by the date specified under subsection (b) of this section. The candidates of the successor unit for Governor and Lieutenant Governor formed under subsection (a)(3) of this section each shall file a certificate of candidacy as a successor unit before the later of: the deadline for filing a certificate of candidacy for the primary election under § 5-303 of this title; or the fifth day following the death, withdrawal, or disqualification of the former candidate.