cDNA library or complementary library is the DNA library constructed from the mRNA which is isolated from the specific tissue.
The genomic library is constructed from the genome sequence of the organism by cutting the gene of interest or the whole genome with a restriction endonuclease and then inserting it into the vectors.
Since the genomic library includes the whole genome which is same in every cell and tissue whereas the cDNA library contains the coding genes expressed in the specific tissue only therefore, Option-B is the correct answer.
