Heraclius was the Emperor of the Byzantine Empire from 610 to
641. He was responsible for reversing the fortunes of war with the Persians in
the first quarter of the seventh century in addition to the introduction
of Greek as the Eastern Roman Empire's official language
Ostrogoths trace their origin to another tribe, the Greuthungi, who were a semi-legendary tribe ( so we're not sure they existed) who dwelled next to the Black Sea- so answer C. is the correct one.
