How is transported soil different from residual soil?

Which of the following statements best explains why there tends to be a greater number of large cities in southern africa than the east africa

What is the general rule about surface currents? cold water flows along the ocean floor towards the equator. the east coasts of continents have cold surface currents, and the west coasts of continents have warm surface currents. seasonal and constant offshore winds create significant upwelling along the west coasts of south and north america and africa. the west coasts of continents have cold surface currents, and the east coasts of continents have warm surface currents.

Which characteristics of temperature and salinity have the greatest influence on the movement of deep-ocean currentsa. warm and low salinityb. cold and high salinityc. cold and low salinityd. warm and high salinity