Which of the following ecosystems has the highest productivity?

Why are oceans the least productive ecosystems?

Which of the following produces the maximum amount of organic matter?

Given below are two statements:
Statement $I$: The primary source of energy in an ecosystem is solar energy.
Statement $II$: The rate of production of organic matter during photosynthesis in an ecosystem is called net primary productivity $\text{(NPP)}$.
In the light of the above statements,choose the most appropriate answer from the options given below:

Primary productivity depends on.........

Explain productivity and its types.