Consider the following statement with respect to ecosystems:
A. Two basic categories of ecosystems are pond and the grassland.
B. Forest, grassland and desert are some example of terrestrial ecosystems.
C. Crop fields and an aquarium may also be considered as natural ecosystems:
D. Pond, lake, wetland, river and estuary are some example of aquatic ecosystems.
Of the above statements:
A. B and D are correct
B. A and B are correct
C. A and C are correct
D. A and D are correct
