Concept:Unisexual flowers contain only male (stamens) or only female (pistil) reproductive parts.Explanation:Papaya flowers are unisexual — separate male and female flowers.Corn and cucumber are other examples of unisexual flowers.Sunflower, hibiscus, and mustard are bisexual flowers because they have both stamens and pistil in the same flower.Therefore, among the given options, only papaya is unisexual.Answer:Option A. Papaya