Explore Westonci.ca, the leading Q&A site where experts provide accurate and helpful answers to all your questions. Connect with a community of experts ready to provide precise solutions to your questions on our user-friendly Q&A platform. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform.

Part A: Identify the oldest rock layer shown in the diagram. Be sure to explain your reasoning.

Part B: Scientists think that the trilobite fossil found only in layer d became extinct soon after layer d was formed. Using evidence from the cross-section, explain why this statement is true or not.