The answer is b. the gravitational pull on materials of varying densities.
To explain would take forever because there is so many things that are involved. One of the main factors is western/Euro influences. As well as people rather ignore reasoning and start fighting.
Manila is the capital of the Phillipines
<span>The southern hemisphere is believed to be older because it has more craters. The northern hemisphere consists of plains and is at a lower elevation. There is an abrupt elevation change at the border between the two hemispheres.</span>