Question

The transformation of ovules into seeds and ovary into fruit proceeds

Answer 1

Post fertilisation events
After fertilisation of the egg cell (female gamete) present within the embryo sac (female gametophyte) by the male gamete, a zygote is formed which develops into an embryo.
In order to protect the growing embryo, the ovule that harbours the embryo sac matures into a seed. Simultaneously, the ovary that bears the ovule, matures into a fruit.

(B) Simultaneously