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.
The Ostrogoths were a Germanic people from the division suffered by the Goths in the third century. The Goths who settled east of the Dniester River, in the lands around the Black Sea (what is now part of present-day Ukraine and Belarus), formed a confederation with the peoples of the steppes known as Greutungos.
The Mexican Cession (Spanish: Cesión mexicana) is the region in the modern-day southwestern United States that Mexico ceded to the U.S. in the Treaty of Guadalupe Hidalgo in 1848 after the Mexican–American War
