In a scenario where 20 transcriptional regulators are bound to a gene, what role does the 21st regulatory protein play?

• A. It acts as an on-off switch, determining whether the gene is expressed.
• B. It has no effect on gene expression as the other 20 regulators are sufficient.
• C. It changes the type of cell the gene is expressed in.
• D. It decreases the expression of the gene by removing other regulators.

Answer: (A)