Which of the Following Is False About Rifamycins

Which of the following is false about rifamycins?

A) They were originally isolated from bacteria.
B) They are broad- spectrum antimicrobials that are effective against most Gram- positive bacteria and some Gram- negative bacteria too.
C) The drugs are useful to combat mycobacterial species that can be especially tough to treat due to the challenges of getting drugs across their waxy mycolic acid- enriched cell wall.
D) Because the chemical structure is such a good fit with RNA polymerase, it is unlikely to cause interactions with any other medications currently known.
E) They inhibit transcription by binding to RNA polymerase.