Monarch butterflies must contend with single-celled parasites that can cause deformities that interfere with their fl...

Irina on January 31, 2020

(D) is correct because the argument confuses cause and effect. Based on the evidence that monarch butterflies that failed to migrate are predominantly infected with parasites, the argument concludes that migrating helps the butterflies avoid the parasite, whereas it is more likely that the reason butterflies failed to migrate in the first place is because the parasite interfered with their flight, meaning it is a consequence rather than the cause.

Does this make sense?