The formation of embryo sac is called

Delete the odd one.

Embryo sac consists of

$A$ : Eight cells of octant stage in dicot embryogeny are made by $2$ vertical and one transverse divisions in
embryonal cell.
$R$ : These cells are arranged in epibasal and hypobasal tier.

In angiosperms, microsporogenesis andmegasporogenesis

In angiosperms, the following events occur during megasporogenesis and megagametogenesis

$(i)$ Differentiation of megaspore mother cells

$(ii)$ Meiosis of the megaspore mother cell

$(iii)$ Formation of a linear tetrad

$(iv)$ Mitotic division of the functional megaspore

$(v)$ Degeneration of 3 megaspores

$(vi)$ Formation of embryo sac

$(vii)$ Fusion of polar nuclei

The correct sequence is