When a foreign piece of DNA is inserted into a plasmid antibiotic resistance gene, the host organism ...

When a foreign piece of DNA is inserted into a plasmid antibiotic resistance gene, the host organism becomes sensitive to this antibiotic. This antibiotic sensitivity is used to selectively identify which plasmids contain the inserted gene of interest. How can this selection be made if the antibiotic now kills off those very organisms containing the plasmids you wish to propagate?
 a. The needed plasmids are extracted from the dead organisms.
 b. The host organisms die, but the plasmids survive by themselves.
 c. The ampicillin sensitivity test is carried on a replica plate of the organisms and not the original plate.
 d. The insertion of the foreign DNA does not completely render the organisms susceptible to the antibiotic and the slow-growing colonies are selected for further study.