Japenese beetles and gypsy moths were accidently introtudec to North America the mot probable reasonn these insect have become serious pests in North America is that they

have few natural enemies and can outcompete native species.
b
are protected by Federal laws.
c
were created in labs by scientists and are resistant to pesticides.
d
became extinct in the late 1980s.

The most probable reason these insects have become serious pests in North America is that they have few natural enemies and can outcompete native species.