Translation:Who is the Prime Minister of Poland?
"who is the polish prime minister?"
Since December 2017 Mateusz Morawiecki is the polish Prime Minister
OK without 'the' I think - Who is Prime Minister of....
I don't believe it is, a country has one Prime Minister at the time, after all...
EDIT at least 2 months later: Well, it turns out that it's okay after all, added.