The correct option is D Single cotyledon in seed
Cotyledons are the food reserve for growing seeds and their number in the seeds can vary. Plants having seeds with a single cotyledon is called monocot. These plants show different morphological characteristics to distinguish them from the dicot plants with seeds having two cotyledons. A monocot plant shows fibrous root system and parallel venation on their leaves (eg: maize), whereas a dicot plant have tap root system and reticulate venation on their leaves (eg: pea).