How does the presence of strong interxn between RNAP and the promoter affect transcription?

The presence of strong interactions between RNA polymerase (RNAP) and the promoter significantly enhances the transcription rate. A strong interaction implies that RNAP has a better affinity for the promoter region, increasing the likelihood that transcription initiation will occur.

When RNA polymerase binds firmly to the promoter, it stabilizes the formation of the transcription initiation complex, thereby facilitating a more efficient transition from initiation to elongation. This strong binding leads to a higher probability that the enzyme will successfully initiate RNA synthesis, resulting in an increased number of RNA transcripts produced over a given period. In contrast, weaker interactions would likely result in reduced initiation events, thereby lowering the rates of transcription.

Given this understanding, it becomes clear why the correct answer highlights the positive effect of robust RNAP-promoter interactions on transcription rates.