Charlemagne was known as the "father of europe.” how does this map to explain that title?

it shows that charlemagne united eastern and western europe.
it shows that charlemagne’s empire was as large as that of the franks.
it shows that charlemagne’s empire was more powerful than the roman empire.
it shows that charlemagne conquered a huge part of europe.

The correct answer is:

It shows that Charlemagne conquered a huge part of Europe.

Charlemagne was granted the title "Father of Europe" (Pater Europe) because he was able to unite a great part of Western Europe for the first time since the Roman Empire´s classical era. Furthermore, he managed to unite parts of Europe that never been had been under Frankish rule before.

Charlemagne was King of the Franks, then became King of the Lombards and finally Holy Roman Emperor. His Carolingian Empire is the developed Frankish state.