Out of the list of biological systems what are two of them and how are these two independent from one another?

the circulatory, respiratory, muscular, digestive, integumentary, endocrine, reproductive, and nervous systems. All of these systems have specific functions but they cannot function independently. They rely on all the other systems in order to work properly.

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.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.