The correct option is A Nandivarman II, Nagabatta I
While the region of South India was ruled by ancient kingdoms such as the Cheras, Cholas, Pallavas, and Pandyas, in Europe, a new institution called the Holy Roman Empire sprung up. In 800 C.E., Charlemagne, the king of Franks, was its first emperor. He was a contemporary of Pallava king Nandivarman II and Pratihara ruler Nagabatta I.