Hello! Fossil fuels are NOT renewable resources. A is out. Burning fossil fuels does produce emissions. B is our. Oil and natural gas does not exist in unlimited quantities, so C is out. However, they are the easiest fuels to make in large amounts, which is why a lot of them are use, despite limited quantities. The answer is D.
The Rocky Mountains are described as younger because the Rocky's are really two mountain chains. The older mountain chain started billions of years ago, and the younger mountain chain pushed the older mountain chain up more, only 60 millions years ago.
They are called fringing reefs. They grow directly from shore and form borders along the shoreline.
When a fringing reef continues to grow upward from a volcanic island that has sunk entirely below the sea level, an atoll is formed. Atolls are usually circular or oval in shape, with an open lagoon in the center.
The fringing reef is the most common type of coral reef. They however tend to be very sensitive to human induced pollution in the water and are easily destroyed by such.