Help me idk the answer to this

Which best describes the digestive system of arthropods? a incomplete, two openings b complete, one opening c two-way, one opening d one-way, two openings

Isolated volcanic peaks on the ocean floor are

There are multiple lines of evidence that provide support for common ancestry and evolution. write 3-4 paragraphs describing at least three of them in detail. provide at least one example for each line of evidence.