Problem:
Question: Expression of the beta-globin gene is regulated by DNA sequences located?
A.in the 5? region just upstream of the promoter and protein coding sequence
B.in the 3? region downstream of the poly-A addition site
C.more than 50,000 basepairs upstream of the promoter and protein coding sequence
D.A and C are both true
E.A, B and C are all true
Please select correct answer and also provide explaination.