The correct option is B C4-Plants
Chloroplast dimorphism is occurence of two different types of chloroplasts and it is observed in C4 plants. The leaves of C4 plants exhibit Kranz anatomy in which the vascular bundles are sorrounded by large bundle sheath cells resembling a wreath. Bundle sheath cells are sorrounded by mesophyll cells.
In mesophyll cells, the chloroplasts have grana and in bundle sheath cells, the chloroplasts are agranal. Occurence of two different type of chloroplasts in the leaves of C4 plants is called chloroplast dimorphism. Maize and sugarcane are C4 plants.