In flowering plants, zygote develops into:

The correct answer is Option (4) → Embryo

Option (4) Embryo — Correct. After fertilisation, the zygote develops into the embryo, the primary endosperm nucleus into the endosperm, the ovule into the seed and the ovary into the fruit.

NCERT Extract:
Double Fertilisation – “… Since two types of fusions, syngamy and triple fusion take place in an embryo sac the phenomenon is termed double fertilisation, an event unique to flowering plants. The central cell after triple fusion becomes the primary endosperm cell (PEC) and develops into the endosperm while the zygote develops into an embryo.”