Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Protostomes and Deuterostomes Bilaterally symmetrical, triploblastic eucoelomates can be divided into two groups based on differences in their early embryonic development. Protostomes include phyla such as arthropods, mollusks, and annelids. Deuterostomes include. Answer: protostomes and deuterostomes
Output:
What are the two groups that tripoblastic eucoelomates can be divided into based on early embryonic development differences?