Efflux pumps send antibiotics, such as the protein synthesis-inhibitor tetracycline, out of the bacterial cells, enabling them to grow in the presence of antibiotics. Which of the following therapeutic approaches will be LEAST effective?

A) Switch to an antibiotic that is not a substrate of the efflux pump.
B) Augment the treatment with an efflux inhibitor.
C) Increase the concentration of tetracycline.
D) Augment the treatment with an ATP synthase inhibitor.
E) Add a second antibiotic to the therapy.