I need some friend to talk to about anything

Hello.the answer is b.they are made using many small pieces of fabric sewn together.have a nice day

The options for this question is 
a.) a private building used for religious purposes
b.) a stadium used for athletic events, chariot racing, and acrobatics
c.) a central building surrounded by religious and governmental buildings
d.) an open space in a town used as a central gathering place or event