You Prepare a Genomic Library and Use This as a Source

Multiple Choice

You prepare a genomic library and use this as a source to produce recombinant proteins in E. coli. However, after producing the proteins you find that they are all too long or too short. In fact, you don't find a single protein that is the correct size. What is the best explanation for this result?

A) Since a genomic library was used as the source of the genes, the introns were included during transcription and translation.
B) Since bacteria were used to produce the proteins, sugar groups were not properly added on to the proteins that were being made.
C) Since a genomic library was used as the source, the recombinant bacterial plasmid DNA was likely incorporated into the proteins being made.
D) Since bacteria were used to produce the proteins, the native bacterial plasmid DNA was likely incorporated into the proteins being made.