The best answer is A. The purpose of the cell wall is to hold the cell in a specific shape, usually rectangular or square. For example, a plant cell's wall keeps it rigid so that the plant can stand up.
If the cell does not have a wall, it can easily change shape to accommodate for things coming in and out of the cell.
Hope this helps!
B. CO2 levels in the atmosphere could increase and contribute to global warming problems.
A rock that is composed of material evaporated from seawater is described as chemical.
