The correct answer is:
c. convection.
The heating of magma and the continuous cycle of evolution of the magma creating a convection current is the reason for the evolution of Earths tectonic plates.
Explanation:
Tectonic plates are ready to move because the Earth's lithosphere has higher strength than the underlying asthenosphere. Lateral density changes in the mantle appear in convection. Plate movement is believed to be driven by a succession of the motion of the seafloor apart from the extended ridge (due to variations in topography and density of the crust.
It really depends on how far or close the planet is from the sun
Molecules in the air scatter blue<span> light from the sun more than they scatter red light.</span>
One is for far distance the other is for close range
Answer:
a) moves down
b) moves down
c) level remains same
Explanation:
Given that the anchor is initially on the floating boat.
a)
In this condition initially the the volume of water
displaced is to balance its weight.
Now,



We've, the density of steel
and the density of water 

When the anchor is dropped into water:
The volume of water displaced be
which will be equal to the volume of anchor since it is immersed into it.

...................(1)
So the level of water falls when the anchor is dropped into water.
b)
Now, when the anchor is thrown on the ground the water has now less weight to balance so the water level falls down.
c)
When the cork on the from the boat is dropped into the water and it still floats then it must displace same amount of water, hence there should be no change in the water level.