In a typical angiosperm embryo sac, the egg apparatus consists of:

The correct answer is Option (1) → two synergids and one egg cell

The embryo sac is the female gametophyte of a flowering plant. A mature embryo sac has 8 nuclei but only 7 cells. Three cells sit at the micropylar end, three at the chalazal end, and one large central cell lies in the middle. The group of three cells at the micropylar end is called the egg apparatus.

Option (1) two synergids and one egg cell — Correct. The egg apparatus is made of two synergids and one egg cell. The synergids have finger-like thickenings called the filiform apparatus, which guide the pollen tube into the synergid. The egg cell later fuses with a male gamete to form the zygote.

Option (2) three antipodals and one egg cell — Incorrect. The three antipodals lie at the chalazal end, the end opposite the egg. They are not part of the egg apparatus.

Option (3) two polar nuclei and one egg cell — Incorrect. The two polar nuclei are not separate cells. They lie inside the large central cell, below the egg apparatus.

Option (4) two synergids and the central cell — Incorrect. The central cell is the large middle cell that holds the polar nuclei. It is not one of the three micropylar cells, so it is not part of the egg apparatus.

NCERT Extract:
The Pistil, Megasporangium (Ovule) and Embryo Sac – “… There is a characteristic distribution of the cells within the embryo sac. Three cells are grouped together at the micropylar end and constitute the egg apparatus. The egg apparatus, in turn, consists of two synergids and one egg cell. The synergids have special cellular thickenings at the micropylar tip called filiform apparatus, which play an important role in guiding the pollen tubes into the synergid. Three cells are at the chalazal end and are called the antipodals. The large central cell, as mentioned earlier, has two polar nuclei.”

Figure 1.8 (c) A diagrammatic representation of the mature embryo sac