Answer: Option D. "Anther"
Explanation:
The stamen is defined as the male reproductive part of flowers that produces pollen in a flower and collective form of stamens is called the androecium.
Their are two parts of stamen, Filament and Anther.
Filament is the stalk of a stamen which supports anther whereas anther are two-lobed responsible for producing pollen.
Hence, the correct option is D, Anther.