In a unisexual male flower, the reproductive organs are typically male (stamens). The stigma, which is part of the female reproductive organ (pistil), is absent in male flowers.
- Option (A) Sepals are present in male flowers, as they protect the flower during bud development.
- Option (B) Petals are often present to attract pollinators, even in male flowers.
- Option (C) Stamens are present in male flowers as they produce pollen.
- Option (D) The stigma is a part of the pistil (female reproductive organ) and is absent in male flowers.
Thus, the correct answer is (D) Stigma.