Which is the most common type of embryo sac in angiosperms?

The most common type of female gametophyte (embryo sac) in angiosperms is the monosporic embryo sac in which the embryo sac develops from a single functional megaspore $(n)$ while the other three megasproes degenerate. The functional megaspore undergoes three sequential mitotic divisions and gives rise to 8-nucleate and 7-celled mature embryo sac.