Answer:
The answer is D. The autonomic nervous system.
Fish poop.
Tropical white beaches get their pearly white color from the excrement of fish far off of the coast which eat coral and other things that reside on the ocean floor. When they eat they swallow some sand into their mouths as well, and process it with the food they just ate. Their stomachs can't really digest the sand, tiny minute rocks essentially, and thus turn their color white. Or the rock forming the sand can be naturally pigmented a whitish tone as well.
G . because the bat population will change with no bugs.
NaCl is dissolved in water so that in a given region or volume the concentration is initially higher in one part than the other l, thus simple diffusion will occur so that there is a net difference or 0, with respect to the concentration of NaCl in a particular volume of water than another. Basically the NaCl will be distributed throughout volume of water.