Answer:
b. transcription
Step-by-step explanation:
Transcription is the process by RNA is synthesized from DNA. It is carried out by RNA Polymerase enzyme which uses DNA as template. It builds new RNA strand in 5' to 3' direction from the template strand. A gene to be transcribed has a promoter region in front of it. RNA Polymerase is required to bind to this region to begin transcription. Once it binds to this region, the two DNA strands separate locally starting the process of transcription.
Rifampin inhibits RNA transcription by inhibiting bacterial DNA dependent RNA Polymerase. It binds to the beta sub unit of RNA Polymerase which does not allow it to properly bind to the promoter region thus halting transcription process.