The correct option is B Malvaceae (Chinarose)
When the stamens of flowers are united as a tube around the style of carpel. It’s the characteristic feature of malvaceae family. 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. When the filaments of all the stamens are joined to form single tube like structure is called as monadelphous e.g., members of Malvaceae.
Therefore, the correct answer is option B.