Which one of the following ecosystems is more productive in terms of carbon dioxide fixation?

$A$: In secondary productivity,no new organic matter is formed.
$R$: It is only the utilisation of part of food manufactured by primary producers in the building of consumer biomass.

Explain productivity and its types.

Approximately $.............$ of the Earth's surface is covered by oceans,yet the productivity of the oceans is only $...............$.

Match List-$I$ with List-$II$ :

List-$I$ (Process)	List-$II$ (Definition)
$A$. Productivity	$I$. Gross primary productivity minus respiration losses
$B$. Net primary productivity	$II$. Rate of formation of new organic matter by consumers
$C$. Gross primary productivity	$III$. Rate of biomass production
$D$. Secondary productivity	$IV$. Rate of production of organic matter during photosynthesis

Choose the correct answer from the options given below:

Secondary productivity is defined as ...