(N/A) The leaves of $C_{4}$ plants exhibit a specialized internal structure known as $Kranz$ anatomy,which distinguishes them from $C_{3}$ plants.
In $Kranz$ anatomy,the vascular bundles are surrounded by a ring of large,specialized cells called bundle-sheath cells.
These bundle-sheath cells contain a high density of chloroplasts,possess thick walls,and lack intercellular spaces.
Furthermore,these cells are impervious to gaseous exchange,which helps in maintaining a high concentration of $CO_{2}$ around the enzyme $RuBisCO$.
This unique anatomical arrangement minimizes photorespiration and enhances the photosynthetic efficiency of $C_{4}$ plants compared to $C_{3}$ plants.