[Grammar] Was or is？

[LiuJing]

Everybody knows one of your sons has won the lottery.
Was that John or Tom? (Is that John or Tom?)


Which tense is correct here?

Thank you.

 

[Harry Smith]

Everybody knows one of your sons has won the lottery.
Was that John or Tom? (Is that John or Tom?)


Which tense is correct here?

Thank you.

Is

 

[LiuJing]

Is

Thank you. Is there any good reason to choose [ is]?

Is it because 'is' matches the present perfect tense?

 

[Harry Smith]

Thank you. Is there any good reason to choose [ is]?

Is it because 'is' matches the present perfect tense?

Yes, and it's also because they are still alive....;-)