Convection is the circular motion that occurs as hotter air or liquid increases when the cooler air or liquid drops down, and has faster moving molecules, rendering it less dense. Convection currents within the earth shift layers of magma, and currents are formed by convection in the ocean.
I think it's A) Sunspots. I hope this helps:)
The earth and moon were created By a collision between two planetary objects Each five time the size of mars. Is the newest hypothesis.
Pretty sure it's C) condensation because all of the others required heat to be added
Explanation:
a) 
where 
is the distance of the mass 
from the axis of rotation. When the axis of rotation is placed at the end of the rod, the moment of inertia is due only to one mass. Therefore,
b) When the axis of rotation is placed on the center of the rod, the moment is due to both masses and the radius r is 1.5 m. Therefore,
