Which type of embryo sac is most common in angiosperms?

Monosporic with three sequential mitotic divisions

The correct answer is Option (2)- Monosporic with three sequential mitotic divisions.

In angiosperms, the formation of the embryo sac, also known as the female gametophyte, involves a process called megasporogenesis. During megasporogenesis, a megaspore mother cell undergoes meiosis to produce four haploid megaspores. Out of these four megaspores, three degenerate, and only one megaspore survives and develops into the embryo sac.

The surviving megaspore then undergoes three sequential mitotic divisions, resulting in the formation of an eight-nucleate structure. These mitotic divisions produce seven cells, including the egg cell, two synergids, three antipodal cells, and two polar nuclei.

Therefore, the correct answer is 2) Monosporic with three sequential mitotic divisions, as it describes the most common pattern of embryo sac development in angiosperms.