You Add an Unknown Phage to a Mixture of F⁺

You add an unknown phage to a mixture of F⁺ and F^- cells of E. coli and plate out the bacteria. The bacterial colonies that grow are all F^-. How can you explain this phenomenon?

A) The phage bound to a receptor on the sex pilus, and therefore only infected the F⁺ cells (leaving the F^- cells alone) .
B) The phage bound to a receptor on the F^- cells, leaving only them alive and allowing the F⁺ cells to die off.
C) The phage integrated (lysogenized) the F^- cells, giving them a selective advantage over the F⁺ cells.
D) F⁺ cells are uniquely susceptible to phage attack for unknown reasons.