The average length of a transcription unit along a eukaryotic DNA molecule is about 27,000 nucleotide pairs, whereas an averaged-sized protein is about 400 amino acids long. What is the best explanation for this fact?


A) Each amino acid in a protein is encoded by a triplet of nucleotides.


B) Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated.


C) Many genes are subject to alternative RNA splicing.