2.Church officials had little power and no land.
That is not true. When it comes to the Catholic Church, they were rich and had plently of land.
3.People often moved into higher social classes.
This was incredibly rare. Most people stayed in their class until their last day.
4.Barons were at the top of the social hierarchy.
Barons were still under plenty of people, including royalty.
The answer is:
1.People were born into a social class
People would be born a noble or a commoner back in that time.