Dimorphism of chloroplast is found in

The correct option is A $C_4$ plants

The most distinct feature of C${}_4$ plants is the presence of bundle sheath with chloroplasts in the leaves. It is like a wreath around the vascular bundle. Hence, such anatomy is called Kranz anatomy. Bundle sheath may be single layered as in maize or double layered as in sugarcane. If two-layered, the outer one is green and the inner one is thick walled and called as the mestomal sheath. Mesophyll cell chloroplasts are granal and starch lacking but the bundle sheath cell chloroplasts are grana-lacking and starch-rich. Such feature of having two types of chloroplasts is known as chloroplast dimorphism.