Answer:
Placenta.
Step-by-step explanation:
The placenta may be defined as the tissue that develops during the gestation period. The placenta connects the mother with the fetus through the umbilical cord.
The main function of placenta is the exchange of nutrients and excretory products between the mother and fetus. The formation of placenta occur in placental mammals. The monkey, dolphins and dogs are placental mammals that has the placenta for the exchange of nutrients.
Thus, the answer is option (C).