How Are Hfr Strains of Bacteria Different from F⁺ Strains

How are Hfr strains of bacteria different from F⁺ strains?

A) Cells of Hfr strains are able to transfer chromosomal genes, whereas cells of F⁺ strains cannot.
B) Cells of Hfr strains cannot initiate conjugation with F^- cells.
C) The F factor is integrated into the bacterial chromosome in all or most cells of an Hfr strain but in only a few cells in an F⁺ strain.
D) Cells of Hfr strains carry F' plasmids, whereas F⁺ cells do not.
E) Cells of Hfr strains can initiate conjugation with F⁺ cells or other Hfr cells.