The correct option is C Trimerous flowers
Trimerous flowers are organized in threes, having parts in numbers that are multiples of three. The monocots typically have trimerous flowers. It is a distinct monocot character shown by the flowers of Liliaceae. In hypogynous flowers, the perianth and stamens are attached to the receptacle below the gynoecium; the ovary is superior to these organs, and the remaining floral organs arise from below the point of origin of the carpel. Examples: Malvaceae, Annonaceae, mustard, china rose and brinjal. Actinomorphic flowers and bisexual flowers are present in plants of Liliaceae, but they are not distinct characters of monocots.
Therefore, the correct answer is option C.