Cell- <span>the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic.</span>
In the thylakoids of the grana, light reactions take place and in the stroma , dark reaction takes place. So all in all, in both places together photosynthesis is carried out
I believe the answer is A, Cholesterol.
The geometric method gives scientists the spreading direction to go with the spreading speed