The era between 1450 and 1750 saw the appearance of several land-based empires who built their power on the use of gunpowder: the Ottomans and the Safavids in Southwest Asia , the Mughals in India , the Ming and Qing in China , and the new Russian Empire.
A vertical relationship involves people who don’t share the same status
The answer would be or because the sentence it gives two different choices in the sentence.
