6. Which of the following best describes siRNA? (A) a double-stranded RNA that is formed by cleavage of hairpin loops in a larger precursor (B) a single-stranded RNA that can, where it has internal complementary base pairs, fold into cloverlcaf patterns (C) a short double-stranded RNA, one of whose strands can complement and inactivate a sequence of mRNA (D) a portion of rRNA that allows it to bind to several ribosomal proteins in forming large or small subunits (E) a molecule, known as Dicer, that can degrade other mRNA sequences