The plan of salvation originated with God the Father.
27 And the Lord said: Whom shall I send? And one answered like unto the Son of Man: Here am I, send me. And another answered and said: Here am I, send me. And the Lord said: I will send the first.
28 And the second was angry, and kept not his first estate; and, at that day, many followed after him.
Elder Bruce R. McConkie said:
“The plan of salvation is the gospel of the Father. The plan of salvation originated with the Father; He is the Author and Finisher of our faith in the final sense; He ordained the laws by obedience to which both we and Christ can become like Him. The Father did not ask for volunteers to propose a plan whereby man might be saved. What He did was ask whom He should send to be the Redeemer in the plan He devised. Christ and Lucifer both volunteered, and the Lord chose His Firstborn and rejected the amendatory offer of the son of the morning.”
(“Our Relationship with the Lord,” in Brigham Young University 1981–82 Fireside and Devotional Speeches , 99.)