Which of the following is the most abundant protein in the chloroplast?

Choose the correct option:
$(1)$ The first product of the $C_3$ pathway in the Calvin cycle is $PGA / OAA$.
$(2)$ The primary acceptor of $CO_2$ in the $C_4$ pathway is $PEP / OAA$.

$A$: Light harvesting complexes $(LHC)$ on thylakoid membrane broaden the range of light absorption.
$R$: They transfer electrons to the reaction centre.

Which of the following products of Hill's reaction are used in Blackman's reaction?

Select the correct option:
$(1)$ $C_4$ plants have double the efficiency of carbon fixation compared to $C_3$ plants.
$(2)$ Sugar is transported from source to sink through the $\text{phloem}$ / $\text{xylem}$ tissue.

Photosynthetic microorganisms ........... .