You are attempting to identify a specific gene that may have been cloned into a gene library. In order to identify which clone is carrying the gene you are looking for you could
A. test each clone for the presence of a molecular marker known to be tightly linked to your gene.
B. probe with an antibody known to bind to the protein your gene codes for.
C. probe each clone with a version of the gene cloned from another species
D. express each cloned gene and test for the enzymatic activity associated with the protein coded for by your gene