How Are RNA Hairpin Turns Related to Transcriptional Termination in E

How are RNA hairpin turns related to transcriptional termination in E. coli?

A) The turns are formed from complementary base pairing and cause separation of the RNA transcript and RNA polymerase.
B) A three-base repeat signals a stop sequence, and the RNA transcript is released.
C) Release factors bind to sites on the hairpin turn, causing release of the RNA transcript.
D) The hairpin turn prevents more nucleoside triphosphates from entering the active site of the enzymes, effectively shutting off the process of polymerization.