12. Small non-coding RNAs function in gene expression and regulation. Which of the following statements about small non-coding RNAs is true? (A) Small nuclear RNAs (snRNAs) primarily guide chemical modifications of other RNAs. (B) Small nucleolar RNAs (snoRNAs) function in pre-mRNA splicing. (C) MicroRNAs (miRNAs) function in RNA silencing and translational regulation. (D) All of the above.