Why were baptisms in the New Testament done immediately?

“8 Crispus, the leader of the synagogue, believed in the Lord with all his household, and many of the Corinthians when they heard were believing and being baptized.” Acts 18

“31 They said, “Believe in the Lord Jesus, and you will be saved, you and your household.” 32 And they spoke the word of the Lord to him together with all who were in his house. 33 And he took them that very hour of the night and washed their wounds, and immediately he was baptized, he and all his household.” Acts 16

“16 ‘Now why do you delay? Get up and be baptized, and wash away your sins, calling on His name.’” Acts 22:16

“37 Now when they heard this, they were pierced to the heart, and said to Peter and the rest of the apostles, “Brethren, what shall we do?” 38 Peter said to them, “Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit. 39 “For the promise is for you and your children and for all who are far off, as many as the Lord our God will call to Himself.” 40 And with many other words he solemnly testified and kept on exhorting them, saying, “Be saved from this perverse generation!” 41 So then, those who had received his word were baptized; and that day there were added about three thousand souls. 42 They were continually devoting themselves to the apostles’ teaching and to fellowship, to the breaking of bread and to prayer.” Acts 2

Multiple choice: Which is True: 1] For no particular reason; 2] Because they were still trusting in works salvation and so they trusted in a work like Baptism to save them instead of trusting in God, or 3] Because they were taught that God saves at Baptism.