What was the capital city of the Ottoman Empire?

Istanbul?

No. That wasn't its name then.

my options are

Istanbul
Baghdad
Jerusalem
medina

All of them are wrong. However, Istanbul used to be called Constantinople. It was still Constantinople while the Ottomans ruled, but changed after the Empire was dissolved.

so it has to be istanbul

Yes.

But whoever made up this question was careless with the truth.

ok thank u

You're welcome.