The correct option is A Nucellus
The mature ovule contains in its central part a region called the nucellus that in turn contains an embryo sac with eight nuclei, each with one set of chromosomes. The two nuclei near the centre are referred to as polar nuclei. In the pines, the female gametophyte develops within the tissues of the nucellus and acquires abundant food reserves. The proembryo forms after a period of free-nuclear division in the zygote, and the tier of cells above the basal four then elongates to form a suspensor which pushes the embryonic group deep into the gametophyte.