California Condors, Large, Predatory Birds That Were Previously on the Edge

California condors, large, predatory birds that were previously on the edge of extinction, have benefited from a program that raises birds in captivity and then releases them into the wild. The reintroduction program, however, is having variable success.
-Which information provides the best evidence to help develop a hypothesis about what is causing the difficulties faced by a coastal condor population?

A) Sea lions, food for condors along the coast, live near an old dumping ground for a chemical manufacturing plant and have a significant amount of DDT in their blubber.
B) Air currents along the coast are stronger, allowing coastal condors to cover more area in their search for prey.
C) California bans ammunition containing lead (Pb) to prevent lead ingestion by condors feeding on carcasses of animals shot by hunters but not retrieved.
D) Hatching success in birds farther from the coast was greater than that in birds along the coast.