Answer:
A
Step-by-step explanation:
The deep cooler currents in the oceans have more nutrients because of several factors;
- They are cold and dense hence can hold much oxygen
- The ‘scrap’ along the ocean floor hence carry with them dissolved mineral elements from the rocky bottom.
- The dead organisms that sink to the bottom of the oceans are carried by these currents.
When the trade winds push the warm waters towards the east, the cooler water from the bottom upwell (from the west in a cyclic fashion) to replace the displaced water by the winds. They bring with them nutrients and oxygen that is great ‘fodder’ for plankton. The plants are then fed on by smaller fish like shrimps. The smaller fish are then preyed on by bigger fish hence sustaining food chains/webs.