In flowering plants, zygote develops into:

Embryo

The correct answer is Option (4) → Embryo

The embryo is the early developmental stage of the plant, which will eventually grow into a new plant. Embryo develops at the micropylar end of the embryo sac where the zygote is situated. Most zygotes divide only after certain amount of endosperm is formed. This is an adaptation to provide assured nutrition to the developing embryo.

 The other options play different roles:

• Cotyledon: This is a part of the embryo that serves as a food storage organ or seed leaf.
• Fruit: The fruit develops from the ovary of the flower and serves to protect the seeds and aid in their dispersal.
• Endosperm: This is a tissue that provides nourishment to the developing embryo. The cells of this tissue are filled with reserve food materials and are used for the nutrition of the developing embryo.

So, the correct answer is: Embryo.