Which is not associated with upwelling?

a. increased plankton population.

b. horizontal water movements.

c. increased nutrients at the ocean surface.

d. vertical water movements.

The correct answer is letter B. Horizontal water movements. Upwelling is a phenomenon that involves the dense's motion because of the wind. It is cooler and makes the water rich in nutrients towards the ocean surface. The warmer air is replaced and nutrient-depleted surface water are also replaced. This makes increase in plankton population and increase in nutrients at the ocean surface. The movement of the water is vertically up.