During Dideoxy Sequencing Reactions,dideoxyribonucleoside Triphosphates DdNTPsare Added in Small Amounts

Multiple Choice

During dideoxy sequencing reactions,dideoxyribonucleoside triphosphates ddNTPsare added in small amounts to terminate the sequencing reaction.How do ddNTPs stop a sequencing reaction?

A) ddNTPs lack a 5′ phosphate group.
B) ddNTPs have a hydroxyl group at their 5′ end.
C) ddNTPs are irreversible inhibitors on polymerases.
D) ddNTPs lack a hydroxyl -OHgroup at their 3′ end.