Question: Evidence that sea urchins are more closely related to frogs than they are to snails is that echinoderms and chordates share which of the following embryological features?
A: An embryonic notochord disappears by the adult stage.
B: Larvae undergo metamorphosis.
C: Early embryos are unable to compensate for missing cells.
D: The pore that forms the mouth develops after the pore that forms the anus.
Please eliminate two incorrect options first, then think it step by step and choose the most proper one option. Your entire response should be in English, and in all capital letters.
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