Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: Medulla The medulla is the region known as the myelencephalon in the embryonic brain. The initial portion of the name, "myel," refers to the significant white matter found in this regionespecially on its exterior, which is continuous with the white. Answer: medulla
A:
What is the region known as the myelencephalon in the embryonic brain?