Which of the following statements about eutrophication is true? a. Eutrophication occurs when excess nutrients are present in aquatic ecosystems, resulting in the increased production of plant life and the subsequent increase in the oxygen levels of the water. b. Eutrophication occurs when excess nutrients are present in aquatic ecosystems, resulting in the increased production of plant life and the subsequent decrease in the oxygen levels of the water. c. Eutrophication involves the overpopulation of aquatic ecosystems with plant and animal life. d. Eutrophication is rarely caused by human activity.

B. Eutrophication occurs when excess nutrients are present in aquatic ecosystems, resulting in the increased production of plant life and the subsequent decrease in the oxygen levels of the water.

Explanation:

Eutrophication, refers to the gradual increase in the concentration of plant nutrients in an aquatic ecosystem that's aging such as a lake.

This then brings about the increased production of plant life and the subsequent decrease in the oxygen levels of the water.

Therefore, the correct option is B.

9.9 years

a = p(1 + rt) . . account balance after time t at rate r starting with principal p

3000 = 2500(1 + 0.0202t) . . filling in the given numbers

1.2 = 1 + 0.0202t . . divide by 2500

0.2 = 0.0202t . . . subtract 1

0.2/0.0202 = t ≈ 9.901

it will take about 9.9 years for the account balance to reach $3000.