The gypsy moth is a species native to Europe that has been brought to the United States. It prefers to feed on oak trees in the U.S., and its caterpillars can consume all of the leaves off of trees. This leads to tree death after a few years of repeated defoliation. 

Why is the gypsy moth able to do so much damage to trees in the United States?

a. It is a non-native species and therefore has fewer predators.

b. It is a parasite and therefore does not need its host to survive.

c. The ecosystems found in the United States are less stable than those in Europe.

d. The gypsy moth is a uniquely dangerous species of insect around the world.
pleaz help asap.