Regulation types--bacteria and antibiotics?

Bacterial strategies to evade natural or human-imposed antibiotics are varied and include membrane-bound efflux pumps that export antibiotics from the cell. A review of efflux pumps states that, because energy is required to drive the pumps, activating them in the absence of the antibiotic has a selective disadvantage. The review also states that a given antibiotic may play a role in the regulation of efflux by interacting with either an activator protein or a repressor protein, depending on the system involved.

Based on this information, how might such systems be categorized in terms of regulation?
Select all types of regulation that are consistent with the information provided.

   negative inducible
   negative repressible
   positive inducible
   positive repressible