Resolves 'YES' if Vance issues written declaration to Congress that Trump is unable to discharge the powers and duties of his office, 

. Resolves 'YES' immediately upon such a declaration, even if Trump is only temporarily divested of authority.

Would also resolve 'YES' if Trump voluntarily transfers presidential authority to Vance, 

  Vance assumes presidential authority for a continuous duration in excess of one week (7 days).

Resolves 'N/A' if Trump is not elected President in 2024.

https://en.wikipedia.org/wiki/Twenty-fifth_Amendment_to_the_United_States_Constitution

 Edited title "If Trump wins the 2024 election, will the 25th Amendment be invoked as to transfer presidential authority?" -> "Will the 25th Amendment be invoked as to transfer presidential authority from Trump?"