The correct answer is New customs and beliefs are adopted
When people migrate in groups, then they adopt new cultural practices based on where they are going and how things are changing. Often they keep their own culture but adapt it to suit the new society where they are found. Also, if a large group splits into two groups that go their own way, their culture usually starts developing differently.
Large areas of Europe were conquered by Muslims. When these areas such as southern Spain were recaptured and placed under Christian rule Muslim customs and architecture remained. Christians were encouraged to go on Crusade to recapture Jerusalem from the Muslims.
