Which of the following contacts may be confirmed through the Logbook of The World (LoTW)?
Why Logbook of The World is ARRL's electronic confirmation system: both operators upload digitally signed logs, and when the QSO details match, LoTW records a confirmation. It is not restricted by the type or location of the contact, so domestic special event QSOs, US-to-DX QSOs, and QSOs needed for Worked All States all count. LoTW credits feed ARRL awards including DXCC, WAS, VUCC and the Triple Play, plus CQ awards such as WPX and WAZ.
Watch out Each individual choice is a real LoTW use, so picking just one (thinking LoTW is only for DXCC/DX contacts) misses that the system confirms any matched QSO.
LoTW confirms any matched QSO, domestic or DX, so the all-inclusive answer wins.