The correct option is C Malvaceae
The androecium is stamens in the flower which forms a whorl surrounding the gynoecium and is inside the perianth. Stamens can be present as free or fused. The fused stamen can be connate, joined in the same whorl or adnate, joined from more than one whorl. Solanaceae family is characterized by the presence of epipetalous stamens in which filaments of stamens are fused with petals. Cruciferae or Brassicaceae is characterized by the presence of synandrous or polyandrous stamen in which only anthers are fused or joined. Monadelphous stamens are fused into a single, compound structure, for example, Malvaceae. Here, the base of the filament of same size stamen is attached to stem and forms a staminal column or staminal tube. Poaceae family is characterized by the presence of free stamens, polyandrous.
Therefore, the correct answer is option C.