Question

Choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal. choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal. protonephridium: earthworm malpighian tubule: frog exchange across the body surface: snake flame bulb: flat worm

Answer 1

I think the answer is the last one; Flame bulb; flat worm.
A flame bulb or a flame cell is a specialized excretory cell found in the simplest fresh water invertebrates, including flatworms, rotifers and nemerteans; these are the simplest animals to have a dedicated excretory system. Bundles of flame cells are called Protonephridia.