How many megaspore mother cells are present inside a nucellus?

The correct option is A 1
The ovule contains the embryo sac. The embryo sac is surrounded by the nucellus. In an ovule, a single cell differentiates into a megaspore mother cell in the micropylar region of the nucellus. The MMC further undergoes meiosis and results in the formation of four megaspores, out of which, only one is functional. The functional megaspore leads to the formation of the female gametophyte or the embryo sac.