I can't vote in the poll, since I don't agree with any of the options.
The Lord's Day is the day of Christ's glorious resurrection, the first day of the week, and celebrated by the Faithful when assembled to hear the word and receive the Lord's Supper.
The Lord's Day is not the Sabbath, it's not a new Sabbath and it's not the Sabbath established as part of the covenant with the Jewish people through Moses. The Sabbath looked forward to Christ, being a shadow of the fullness of Jesus who has brought us into His rest through the salvation we have received in and from Him. And therefore, as the author of Hebrews says, there remains a rest for the people of God, today (Hebrews 4:1-12)--by trusting in God's promises in Christ, in the Gospel of our salvation and God's grace, we experience this rest--apart from faith in the Gospel we are without it. So Christ says, "Come to Me all you who are weary and overburdened, and I will give you rest" (Matthew 11:28-30).
Christ is Himself our Sabbath. The Lord's Day isn't our Sabbath, but the day the Church has, from the beginning, come together to assemble for Word and Sacrament, that we might be continually refreshed in the goodness of God which is ours in Christ. We do this on the Lord's Day, the weekly commemoration of Christ's glorious resurrection, because His resurrection is the central truth of who we are as God's people: For Christ who suffered and died for our sins has been raised up, defeating sin, death, hell, and the devil; and His victory is our victory, and so as a people who having been united to His death having also been united to His resurrected life (Romans 6:3-5), having received the Spirit as the seal of our faith and guarantee of God's promises by the power of the Gospel (Ephesians 1:13-14), that we should daily be strengthened in these things. Holding firm to what we have received, clinging to Christ in all things, and depending entirely on God's grace which is the only thing which shall keep us steady through the rumble and tumble and unstable waters of this world--till the day we finally arrive on that distant shore.
God, therefore, having shared with us such an abundance of gifts calls us to abide always in Christ; and that we should enjoy and partake of these good things we come together. And historically, since the beginning, the weekly celebration of these things has been on the weekly commemoration of Christ's resurrection, which the Church has called the Lord's Day. There exists no command from God on what day(s) to assemble, and the people of God assemble regularly on many days. But this weekly day of assembly has always been the prominent one--not out of a legal compulsion; but out of holy freedom, to celebrate the most central truth of our religion: Christ is risen from the dead.
-CryptoLutheran