Choose the correctly written sentence.
a) many of the everglades pythons are very large. because they have abundant sources of food.
b) scientists are concerned that the presence of the introduced species will upset the natural balance, they will eat too many endangered animals.
c) the snakes are very large; however, their color makes it easy for them to hide in the swampy environment.
d) experts became alarmed when a photograph was taken by a python killing an alligator it was that big.