In humans, an XO individual has how many barr body in her cells

In humans, an XO individual has no Barr body in her cells.
A Barr body or X-chromatin is an inactive X chromosome in a cell with more than one X chromosome.
Someone with two X chromosomes (such as most human females) has only one Barr body per somatic cell, while someone with one X chromosome (such as most human males) has none.
Thus as an XO individual has only one X chromosome therefore there will not be any Barr body in its cells.