Red molluscs arrive on New Mexico's beaches to lay eggs during early March. Some native shorebirds depend on these eggs for food during their annual spring migration to their northern breeding grounds. New Mexico's Mollusc population has declined recently. This decline, however, poses no serious threat to the migrating shorebird populations: by remaining longer in New Mexico, the birds will be able to eat enough eggs to allow them to complete their migration.
Which of the following, if true, most seriously weakens the argument?
A. More Red Molluscs are found on New Mexico's beaches than in any other area that the migrating birds pass through.
B. Red molluscs do not conceal their eggs.
C. Amongst the foods available to the birds on New Mexico's beaches, Mollusc eggs are the most nutritious and accessible.
D. Extensive harvesting of Red molluscs by humans is responsible for the decline in the number of Red molluscs on New Mexico's beaches.
E. The earlier in the season the shorebirds complete their migration, the more likely they are to breed successfully.