Which question,arising from the results depicted in the above figure,is most interesting from a genetic perspective,and has the greatest potential to increase our knowledge base?

A)If reciprocal crossing over could occur even if the piece of donated Hfr DNA were identical to the homologous portion of the recipient's chromosome, what prevents this from occurring?
B)What forces are generally responsible for disrupting the sex pilus?
C)How is it that a recipient cell does not necessarily become an Hfr cell as the result of conjugation with an Hfr cell?
D)What makes a cell an Hfr cell?