Answer:
C. The fetus needs large amounts of calcium, iron, and protein from the mother's diet.
Step-by-step explanation:
1. Fetal growth: While it is commonly believed that the fetus grows the most during the third trimester, the statement (A) "The fetus grows the least during this trimester" is inaccurate. In reality, the fetus undergoes significant growth throughout the pregnancy, with rapid development occurring during the second and third trimesters.
2. Embryo development: The period during which the embryo differentiates and develops its various organ systems is the first trimester, not the third trimester. This makes a statement (B) incorrect.
3. Nutritional needs: The third trimester is a critical period for the development and growth of the fetus. As the fetus continues to mature, its demand for essential nutrients increases. Statement (C) correctly highlights that during the third trimester, the fetus requires more significant amounts of calcium, iron, and protein from the mother's diet to support its growth and development.
4. Placental establishment: The establishment and development of the placenta occur early in pregnancy, during the first trimester. Therefore, statement (D), "It is the period during which the placenta becomes well established," is not valid for the third trimester.