B looks like the best to me
Answer AND Explanation:
As light reflected from an external object enters the eye, it is refracted by the cornea, aqueous humour, the lens and vitreous humour so that an image is focused on the retina. The image is real, upside down and smaller than the object. The photoreceptor cells are stimulated by the reflected light and impulses are set off. The impulses are transmitted by neurons through the optic nerve to the optic region of the brain. The brain interprets the impulse as an upright impression of the object.
Answer;
-Down the concentration gradients; evenly distributed
Diffusing molecules move down the concentration gradients until they are evenly distributed.
Explanation;
Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.
-Whenever a substance exists in greater concentration on one side of a semipermeable membrane, such as cell membranes, any substance that can move down its concentration gradient across the membrane will do so. If the substances can move across the cell membrane without the cell expending energy, the movement of molecules is called passive transport.
-The mechanism of molecules moving across a cell membrane from the side where they are more concentrated to the side where they are less concentrated is a form of passive transport called simple diffusion.
You could say DNA is found in both viruses and in living single-celled organisms because DNA is necessary to replicate itself.