Which of the following is the first stable product in the $C_3$ and $C_4$ cycle of photosynthesis,respectively?

Photosynthesis is a $..............$ process.

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

The most vital process for the existence of life on Earth is

$I.$ Initial $CO_{2}$ acceptor
$II.$ Extent of photorespiration
$III.$ Enzyme catalyzing reaction that fixes $CO_{2}$
$IV.$ Presence of Calvin cycle
$V.$ Leaf anatomy
Which one does not differ in a $C_{3}$ and $C_{4}$ plant?

Which of the following is true for photosynthesis?