The answer is A: anther, as it is part of the flower's male reproductive organ.
Flower Anatomy via kwout
Anthers are bright yellow sacs that produce and contain the pollen grains.
Female reproductive system includes an ovary (where the ovules are produced; ovules are the female reproductive cells, the eggs), a style (a tube on top of the ovary), and a stigma (which receives the pollen during fertilization).
The flower is the reproductive unit of some plants (angiosperms). Parts of the flower include petals, sepals, one or more carpels (the female reproductive organs), and stamens (the male reproductive organs).
Flower gardens can turn an ordinary area into a colorful showcase or create a border that pops. Whether you choose an easy to manage perennial or a particularly touchy annual, growing flowers is a rewarding addition to any yard or landscape.
Check out some tips on how to grow flowers at Planetnatural.com.