Which of the following statements about genetic exchange in bacteria is NOT true?

A、In conjugation there has to be a physical connection between the donor cell and the recipient cell.;
B、Plasmids do not have to integrate into the host cell chromosome in order to be replicated.;
C、Interrupted conjugation results in the production of Hfr strains.;
D、Antibiotic resistance can be transferred from one bacterial cell to another by conjugation.