Why do you suppose plants and forests appeared in large numbers before large animals did? Several of the choices may be correct. Select the options you expect to be the strongest contributing factors.

Choose one or more:
A. Plants had to change less to survive on land.
B. Animals need food, and there was none on land before plants.
C. The increased oxygen levels produced by land plants accelerated animal evolution.
D. The order was pure chance and could have gone either way.
E. Animals are more susceptible to radiation and needed more ozone in order to survive out of the water.
F. It was too cold for animals at first.
G. There was not enough oxygen for lungs to be effective before plants colonized land.
H. Plants were driven to land by scarce resources in the oceans, such as light and minerals.