The correct option is D presence of stomata
The internal structure of monocot leaf is similar to dicot leaf in the presence of stomata. Stomata are present in the epidermis of both dicot and monocot leaves. Each stoma has two guard cells that enclose a stomatal pore. Stomata help in gaseous exchange and transpiration.
But dicot and monocot leaves differ in the arrangement of stomata. In dicot leaves, the lower epidermis has more number of stomata when compared to the upper epidermis. In monocot leaves, stomata are equally distributed both in the upper and lower epidermis.
The mesophyll is the parenchymatous ground tissue present in both dicot and monocot leaves and helps in photosynthesis.