Final answer:
In eukaryotes, the role of bacterial sigma factors is performed by general transcription factors, especially the TFIID complex, in guiding RNA polymerase II to the promoter to initiate transcription.
Step-by-step explanation:
The function of bacterial sigma factors in prokaryotes is analogous to the role of general transcription factors in eukaryotes. Sigma factors in bacteria are responsible for guiding RNA polymerase to the correct promoter site to initiate transcription. Similarly, in eukaryotes, a complex of transcription factors, collectively known as general transcription factors, binds to the promoter region and is essential for the recruitment of RNA polymerase II to initiate the transcription of genes.
Therefore, the correct answer to the student's question is A. general transcription factors. These factors, particularly the TFIID complex which includes the TATA-binding protein, are responsible for recognizing and binding to eukaryotic promoter regions, analogous to the sigma factor's function in prokaryotes.