Solution

Persistant calyx is characteristics of Solanum of Solanaceae. In the great majority of species, the flowers have a differentiated perianth with a calyx and corolla an androecium with five stamens and two carpels forming a gynoecium with a superior ovary. The stamens are epipetalous and are typically present in multiples of four or five, most commonly four or eight. They usually have a hypogynous disk. The calyx is gamosepalous.
Therefore, the correct answer is option D.