Question: The 2015 Bahrain GP2 Series' first race was won by a driver who hailed from what country?
Sentence (from "2015 Bahrain GP2 Series round"): The 2015 Bahrain GP2 Series round was a pair of motor races held on 18 and 19 April 2015 at the Bahrain International Circuit in Sakhir, Bahrain as part of the GP2 Series.
Relevant evidence: Yes