verbs - Which tense is correct? "Bob wanted to know if he is/was a father"

Bob wants to know if he is a father or not. A day later, Bob learns that he's a father. Then three years pass.

Now which of the following is correct and why?

1. Three years ago, Bob wanted to know if he is a father or not.




2. Three years ago, Bob wanted to know if he was a father or not.

Any help is appreciated! But I would greatly appreciate an explanation with your answer. Thank you!