A liver-specific gene was cloned and then subjected to promoter bashing. Five regions adjacent regions A, B, C, D, E were deleted. A is farthest away from the start codon. The DNA was transformed into liver cells. The data from this experiment:
Percentage of
Region Deleted β-Galactosidase Activity
None 100
A 17
B 100
C 745
D 5
E

Question

A liver-specific gene was cloned and then subjected to promoter bashing. Five regions adjacent regions A, B, C, D, E were deleted. A is farthest away from the start codon. The DNA was transformed into liver cells. The data from this experiment:
                                 	Percentage of
Region Deleted      	β-Galactosidase Activity
        	None           	100
        	A                 	17
        	B                 	100
        	C                 	745
        	D                    	5
        	E                  	<1
where are enhancers, silencers, and/or the core promoter at?