<u>Answer:</u>
A is a DNA sequence that binds regulatory proteins that interact with promoter-bound proteins to activate transcription.
<u>Explanation:</u>
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.
I believe its your heart if I am not mistaken hope this helps ^^;
Splicing, adding of the cap and tail, and the exit of the mRNA from the nucleus.
C Improper signaling by the right-left axis during development
