Answer:
b. them
Explanation:
their is used to show ownership
Ex: those are THEIR glasses
They is used to refer to a group of people or someones unknown gender
Ex: There THEY are
It is used to refer to objects
Ex: IT is a ball
there is more to it but this is a simple explanation
A house built with strips of sod and laid like brickwork. Used by settlers of the Great Plains when timber was scarce.