To solve this question, we need to determine the approximate week during pregnancy when the placenta forms.
1. Development of Placenta:
The placenta begins to form around the end of the first trimester, which is typically around 12 weeks of pregnancy. During this period, the placenta develops to facilitate nutrient and gas exchange between the mother and fetus.
2. Evaluating the Options:
Final Answer:
The correct answer is (C) 12 weeks.