The stamen consists of a long stalk called the filament that supports the
stigma
sepal
style
anther

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.