A is a DNA sequence where RNA polymerase binds and begins the process of transcription. A is a DNA sequence that binds regulatory proteins that interact with promoter-bound proteins to activate transcription. A is a DNA sequence that binds regulatory proteins that inhibit transcription. is the protein complex that is part of the RNA interference (RNAi) mechanism. It denatures short double-stranded RNAs to single strands that carry out RNAi. is the enzyme complex that is active in RNAi, where it cuts double-stranded regulatory RNAs into 21-bp to 26-bp segments that are subsequently denatured by RISC.

A is a DNA sequence that binds regulatory proteins that interact with promoter-bound proteins to activate transcription.

Explanation:

Background Knowledge:

DNA contains genes which is a particular segment of DNA. A gene usually has regulatory regions and a structural region.

Promoter: The regulatory region located to the 5 prime end of coding strand of the gene which is called as promoter that controls the binding RNA Polymerase during transcription.

The Terminator is the other regulatory region, located to the 3 prime end of coding strand of the gene. The terminator region causes RNA polymerase to stop transcription.

Structural region is the region present between the promoter and terminator.

Answer of the question is:

A is a DNA sequence that binds regulatory proteins that interact with promoter-bound proteins to activate transcription.