A) Taiga
This is shown by the cold winters and the animal life in the example.
The green house effect occurs when carbon dioxide and water vapor form an invisible blanket around the globe that allows the sun's light to enter, but traps the heat. Green house effect is a process that warms the Earth's surface. When the sun's energy reaches the Earth's atmosphere, some of it is reflected back to the space and the rest is absorbed and re-radiated by greenhouse gases.
The barnacles are only able to attach them selfs to surfaces in the water. Since the surface is limited, barnacles are attaching themselves to the other barnacles, crowding the rock. The muscles were not able to grow or attach themselves off the surface of the rock. Same thing with the mussels that are growing on the rock. So not only barnacles are crowding the rock, but Mussels as well are crowding the rock.
Answer: increased
Explanation: the more you have the better you can tell where something is acting on you, ie touch