Which explains upwelling in the oceans?
a. coastal winds blow cold surface water out to sea. deeper, nutrient-rich, warm water flows upward to replace the surface water.
b. wind near the coastline blows warm surface water away from the land. deeper, nutrient-rich, cold water flows upward to replace the surface water.
c. solar heating near the coastline heats cold surface water, which diffuses out to sea. deeper, nutrient-rich, warm water flows upward to replace the surface water.
d. solar heating near the coastline heats warm surface water, which diffuses out to sea. deeper, nutrient-rich, cold water flows upward to replace the surface water.