单选题 DNA上某段碱基顺序为：5'-ACTAGTCAG-3'，转录后的mRNA相应的碱基顺序是

• A.5'-TGATCAGTC-3'
• B.5'-UGAUCAGUC-3'
• C.5'-CUGACUAGU-3'
• D.5'-CTGACTAGT-3'
• E.5'-CAGCUGACU-3'