What is the crust beneath the Atlantic Ocean like?

thinner than the crust below Australia
thicker than the crust below Australia
mostly made of granite and limestone
mostly made of iron and nickel

Which of these is an example of land degradation? a. containers designed to store pollutants leak. b. fertilizers provide too many nutrients to crops. c. garbage is buried so the land can be reclaimed later. d. a drought kills all the plants in an area, leaving bare land