This affirms the assumption that poisonous butterflies don’t have the irregular flight style. If this were not true, then that would suggest the flight style might not have to do with avoiding predators, because poisonous butterflies wouldn’t need to avoid them.

Whether predators are the most common cause of death doesn’t relate to the purpose of the irregular flight style. Butterflies could fly irregularly to avoid predators regardless of whether they are the most common or second most common cause of death.

But are those other types of butterfly nonpoisonous? And do they use the flight style to avoid predators? Without knowing the answer to these questions, (C) doesn’t help connect the red admiral’s flight style to avoiding predators.

We already know from the premises that the irregular flight style is not energy efficient. Whether it’s more efficient for red admirals than it would be for other insects has no impact. It’s not energy efficient for red admirals.

And do the other nonpoisonous butterflies try to fly irregularly? Without knowing the answer to this question, (E) doesn’t have a clear impact on the relationship between the red admiral’s flight pattern and whether its used to avoid predators.