Which of the following statements is the most likely explanation for why teak wood is water-resistant?
a. it has been genetically modified to be that way.
b. once it is cut down, it is treated with water-resistant sealant.
c. it evolved that way from growing in a region with frequent rains.
d. it first grows underwater and is later replanted above ground.

The most logical answer sounds like D.
If it grows underwater then of course it's able to withstand water. 

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust. 

The answer is the magnetosphere.