Final answer:
Transcription is primarily directed by enzymes, particularly RNA polymerase and various proteins and transcription factors that regulate the process.
Step-by-step explanation:
Like most cellular processes, transcription is directed by the action of enzymes. Transcription is the process in which a segment of DNA is copied into messenger RNA (mRNA), which is then used as a template for protein synthesis during translation. The enzyme responsible for catalyzing the synthesis of RNA from the DNA template is called RNA polymerase. In the transcription process, various other proteins and transcription factors are involved in initiating and regulating transcription, ensuring that genes are expressed at the right times and in the right amounts.
Enzymes are critical for almost all biochemical reactions within the cell, including fatty acid synthesis, where acetyl-CoA carboxylase plays a key role. Similarly, transcription factors act as enzymes that bind to specific sequences on DNA and help in the regulation of transcription. Thus, choices B (fatty acids), C (monosaccharides), and D (inhibitors) are not directly responsible for the action of directing transcription.