The correct option is C unisexual
Essential organs of the flower are androecium and gynoecium which helps in the sexual reproduction of the plant. They are called essential whorls. Calyx and corolla are the accessory organs. Based on the presence or absence of the essential whorls, the flower is said to be unisexual or bisexual.
A flower containing either stamens or pistils is called unisexual flower. These are of two types namely staminate which bear the stamens and pistillate bearing pistils.
If the flower has both stamen and pistil then it is called bisexual flower.
If the fruit is formed without fertilization of the ovary then it is called parthenocarpic fruit.