That was a question that he'd gone over again and again in his mind. If he'd been running the interview, it would have been the first question he'd ask too. Though he had different reasons for wanting to ask it.
Superman was silent for a moment as he went over the answer that he'd rehearsed. Once she printed this, it would be all over in some ways. There would be no doubt in anyone's minds that he was an alien. No chance that he was just a guy in a special suit or some sort of super human.
Lois obviously didn't mind and that bolstered him and encouraged him onward.
"I'm from a planet called Krypton. From what little I can piece together of my past, I am the last of my kind. My parents sent me to Earth as my planet was dying."
There was a trace of sadness in his voice, though he kept himself professional and controlled. He wondered if it would allay fears to learn that there weren't more 'supermen' headed toward Earth. Assuming that those who would fear such things believed him.