The correct option is A ovary, ovule
Flowers are the reproductive part of a plant. It consist of sepals, petals, stamens and Pistil. Stamens and pistil produce the male(pollen) and female(egg) gamete respectively.
When the pollen grain lands on the stigma it develops a pollen tube and carries male gametes to the ovule.
Then the fusion of male and the female gametes takes place. And this process is called fertilisation.
As a result of fertilisation, the ovary develops into a fruit whereas the ovule develops into the seed.