I think the cytoskeletal protein that helps a cell maintain its shape is actin.
The question is asking to states on how i earth's early lang environment different than today's land environment and base on my research, I would say that in the past centuries or early ages, the Earth's land environment are compost of tree and plants and the air is still fresh. I hope you are satisfied with my answer and feel free too ask for more
The answers are A: It will not make enough food, and C: It will not convert enough CO2 into Glucose.
D is the answer. Since it’s caused by a subduction.