Which letter indicates the extent of Islam's spread 100 years after Muhammed's death?

You didn't include the map, so I can't be entirely sure, but if it's the same test that I have, it's B.

I believe it's Egypt and Persia

The conquest of the Egyptian Regions into Muslim was being done by the Persian Empire Which was led by King Khorsau II

Before the conquest, this region belonged to the Byzantine empire who held Catholic as its main religions