Speculate on the Diversity of Life on Earth If Plants

Speculate on the diversity of life on Earth if plants had never evolved.

A) The existence of large multicellular consumers such as animals and fungi would be unlikely.
B) No atmospheric oxygen would exist and the cell metabolism used by animals and fungi would not be possible.
C) Bacterial life would display a greatly expanded diversity since the competition created by plants would have been absent.
D) Photosynthetic species belonging to the fungi and animal kingdoms would surely have evolved.