I want to know the answer to the following question:
What percent of polychaetes produce yolk-rich eggs?
All the background I'm provided with is that "The rest care for the fertilized eggs until they hatch – some by producing jelly-covered masses of eggs which they tend, some by attaching the eggs to their bodies and a few species by keeping the eggs within their bodies until they hatch.". Is that enough to answer the question?
Answer: no