DNA Libraries Are Constructed and Screened for Genes of Interest

DNA libraries are constructed and screened for genes of interest.If you were interested in identifying genes expressed in cancer cells,why might you choose to use a cDNA library instead of a genomic DNA library?

A) A cDNA library is larger in quantitythan a genomic library is.
B) A cDNA library is enriched for genes that are actively transcribed in your cell of interest.
C) A cDNA library is enriched with noncoding DNA.
D) A cDNA library is enriched for genes that are expressed at low frequency.
E) all of the above