A Bacterial Cell Containing an F Factor Is a Threonine

Multiple Choice

A bacterial cell containing an F factor is a threonine prototroph. Conjugation occurs with an F^- threonine auxotrophic cell. The exconjugant cell can grow on medium lacking threonine. Where was the F factor in the donor cell?

A) F plasmid
B) Hfr chromosome
C) R plasmid
D) A or B are both possible.
E) A, B, or C are all possible.