The answer is D. You know that A is wrong because the nucleus is in the center of a cell. And C is wrong because that is what is fills up the cell (the gooey filling). And B is wrong simply because animal cells lack a cell wall, only plant cells have cell walls.
Can you give me further explanation? For example, how is your phone not letting you download things? What model of a phone is it? what update is it on? and to what extent can you download something?
