The correct answer is A, the clip demonstrates a fertilized egg containing a live larva inside.  Fertile eggs of Ascaris lumbricoides embryonate and become infective after 18 days to several weeks, depending on the environmental conditions.  After infective eggs are swallowed, the larvae hatch, invade the intestinal mucosa, and are carried via the portal vein to the lungs via systemic circulation.  The larvae mature further in the lungs (10 to 14 days), penetrate the alveolar walls, ascend the bronchial tree to the throat, and are swallowed.  Upon reaching the small intestine, they develop into adult worms.

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