Convert the following sentence from Direct Speech to Indirect Speech: He said, "I have worked, so hard for this." Choose the correct options:

He said that he had worked very hard for that. He said that he has worked so hard for. He said that he was going to work so hard for that. He said that he had worked very hard for this.

He said that he had worked very hard for that.

The correct answer is Option (1) - He said that he had worked very hard for that.