What is the correct indirect form of: "By God," he said, "I will never do this again."

1. ক
   He swore by God that he would never do that again.
2. খ
   He promised by God that he will never do this again.
3. গ
   He said by God that he would never do this again.
4. ঘ
   Swearing by God, he said that he will never do this.