51. RNA interference is a technique commonly used to modulate gene expression.Which of the following descriptions about this technology is incorrect?
(A) Double-stranded RNA usually produces better interference efiect than single-stranded RNA docs.
(B) The RNA delivered into the cell is first trimmed into 21-23 nucleotide siRNAby the endoribonuclease Dicer.
(C) siRNA binds to the target gene promoter and prevents transcription throughthe action of the RNA-induced silencing complex (RISC).
(D) RISC has RNA helicase and RNase H activities.
(E) RISC can cleave the mRNA bound by siRNA, so that the protein cannot betranslated.