Final answer:
Option d) Rifampin inhibits RNA metabolism in bacterial cells by blocking RNA polymerase activity, preventing the initiation of RNA transcription.
Step-by-step explanation:
The question you've asked is which of the following inhibits RNA metabolism in the bacterial cell. The correct answer is d) Rifampin.
Rifampin is a semisynthetic member of the rifamycin family and works by blocking RNA polymerase activity in bacteria. This effect inhibits RNA metabolism by preventing the initiation phase of RNA transcription, making it difficult for bacteria to synthesize proteins. Other options, such as Ciprofloxacin, Chloramphenicol, and Trimethoprim, have different targets. Ciprofloxacin inhibits DNA gyrase, while Chloramphenicol and Tetracycline affect protein synthesis by acting on the ribosome -- Chloramphenicol blocks peptidyl transfer and stops protein chain growth, and Tetracycline affects tRNA binding to the ribosome.