Q: What does the placenta sustain during pregnancy?


Read this paragraph and choose the correct option from the provided answers:

Placental mammals are therian mammals in which a placenta develops during pregnancy. The placenta sustains the fetus while it grows inside the mother’s uterus. Placental mammals give birth to relatively large and mature infants. Most mammals are placental mammals.

 Choices:

- the heart

- the mother

- the endocrine system

- the fetus


A:
the fetus