A Barr Body Is A(n)

A Barr body is a(n) :

A) gene on the X chromosome that is responsible for female development.
B) patch of cells that has a phenotype different from surrounding cells because of variable X inactivation.
C) inactivated X chromosome, visible in the nucleus of a cell that is normally from a female mammal.
D) extra X chromosome in a cell that is the result of nondisjunction.
E) extra Y chromosome in a cell that is the result of nondisjunction.