What percentage of usable radiant energy entering a reaction site of photosynthesis is converted to potential energy (in $\%$)?

Consider the following statements regarding photosynthesis and respiration in plants and select the correct option.
$I$. RuBisCO has high affinity to oxygen in low $CO_2$ concentration.
$II$. The Calvin pathway occurs in the chloroplast of bundle sheath cells of $C_4$ plants.
$III$. Yeast poison themselves when the concentration of alcohol reaches $7\%$.
$IV$. Oxygen is a final hydrogen acceptor during aerobic respiration.

Analogy type question:
$(1)$ Biosynthetic phase : Based on $CO_2$ and $H_2O$ :: Phosphorylation : ......
$(2)$ First product of $C_3$ cycle : $PGA$ :: First product of $C_4$ cycle : ......

Plants produce food through .......,in which ......... conversion takes place.

What is the unique process which has supported life on this planet?

Which of the following categories of photosynthetic plants has the lowest transpiration ratio $(TR)$?