Detailed Instructions: In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.
Q: Question: What do you call an animal in which the embryo, often termed a joey, is born immature and must complete its development outside the mother's body? Answer: marsupial
A:
You call an animal in which the embryo, often termed a joey, is born immature and must complete its development outside the mother's body a(n) marsupial.