The total energy fixed by a gram plant ($Cicer$ $arietinum$) in an ecosystem on the whole is called

Primary productivity is defined as:

In which form can the productivity of ecosystems be compared?

The rate at which energy is stored at the level of primary consumers is known as:

$A$ is required for higher primary productivity. $B$ have the lowest primary productivity as the soil is deficient in moisture.
Choose the correct option for $A$ and $B$.

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: