Which of the following facilitates the supply of oxygen and nutrients…

The correct answer is Option (1) → Placenta

After implantation, chorionic villi grow out from the trophoblast and interdigitate with the uterine tissue. Together they form the placenta, the structural and functional link between the embryo and the mother.

Option (1) Placenta — Correct. The placenta brings oxygen and nutrients to the embryo and removes carbon dioxide and excretory wastes produced by it. It is joined to the embryo by the umbilical cord.

Option (2) Graafian follicle — Incorrect. The Graafian follicle is the mature follicle in the ovary. It ruptures at ovulation to release the secondary oocyte, long before any embryo exists.

Option (3) Corpus luteum — Incorrect. The corpus luteum forms from the ruptured Graafian follicle and secretes large amounts of progesterone. It keeps the endometrium ready, but it does not carry oxygen or food to the embryo.

Option (4) Inner cell mass — Incorrect. The inner cell mass is the group of cells inside the blastocyst that becomes the embryo itself. It receives nutrients; it does not supply them.

NCERT Extract:
Fertilisation and Implantation – “… The blastomeres in the blastocyst are arranged into an outer layer called trophoblast and an inner group of cells attached to trophoblast called the inner cell mass.”
Pregnancy and Embryonic Development – “After implantation, finger-like projections appear on the trophoblast called chorionic villi which are surrounded by the uterine tissue and maternal blood. The chorionic villi and uterine tissue become interdigitated with each other and jointly form a structural and functional unit between developing embryo (foetus) and maternal body called placenta (Figure 2.12). The placenta facilitate the supply of oxygen and nutrients to the embryo and also removal of carbon dioxide and excretory/waste materials produced by the embryo.”