Which of the following contribute to the carbon cycle?

The phosphates remain outside the natural cycle for a long time:

Given below are two statements:
Statement $I$: In an ecosystem,there is a unidirectional flow of energy from the sun through producers to consumers.
Statement $II$: Ecosystems are exempted from the $2^{nd}$ law of thermodynamics.
In the light of the above statements,choose the most appropriate answer from the options given below:

The given food web contains some missing organisms $A, B, C$ and $D$. Identify these organisms and select the correct answer.

Which light is transmitted by water?

Which of the following ecosystems is both man-made and aquatic?