Over the past century, the percent of squirrels in the vicinity of Washington, DC, that are black instead of the more common gray has been continually
increasing. Which of the following statements best explains why this is happening?
OA. Gray squirrels are more comfortable with humans than black squirrels.
OB. Black squirrels are more visible against tree trunks than gray squirrels.
Oc. Black squirrels are more popular with tourists than gray squirrels.
OD. Black squirrels have a survival advantage over gray squirrels.

Black squirrels have a survival advantage over gray squirrels

Black squirrels have a survival advantage over gray squirrels

Explanation:

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation:

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.