If a plant is exposed to $^{14}CO_2$ in the dark and then transferred to light, the $^{14}C$ label will appear first in which of the following carbohydrates?

I. Initial $C{O_2}$ acceptor

II. Extent of photorespiration

III. Enzyme catalysing reaction that fixes $C{O_2}$

IV. Presence of Calvin cycle

V. Leaf anatomy

Which one does not differ in a ${C_3}$ and ${C_4} -$ plants?

The first product of $C{O_2}$ fixation in ${C_4}$ pathway is

PEP carboxylase

I. is involved in atleast some $C{O_2}$ fixation in both ${C_3}$ and ${C_4} -$ plants

II. Catalyses the reaction of fixing $C{O_2}$ into pyruvic acid in bundle sheath cells

III. is capable of fixing $C{O_2}$ more efficiently at lower atmospheric $C{O_2}$ concentration than RuBP carboxylase

Select the correct option