Duchenne muscular dystrophy is caused by a mutation in a gene that comprises 2.5 million base pairs and specifies a protein called dystrophin. However, less than 1% of the gene actually encodes the amino acids in the dystrophin protein. On the basis of what you now know about gene structure and RNA processing in eukaryotic cells, provide a possible explanation for why less than 1% of the gene encodes the dystrophin protein.

a. It is likely that the addition of the 5′ cap contributes to the majority of the mRNA degrading, preventing its ability to be used for protein production.
b. It is likely that the 5′ cap serves as an indicator for a smaller region of the gene to be used for translation of the protein.
c. It is likely that during the splicing process, a majority of the pre‑mRNA is removed in an effort to splice out all the introns.
d. It is likely that during the splicing process, a majority of the pre‑mRNA is removed in an effort to splice out all the exons.