Which of the following is an unsegmented acoelomate worm? a. flatworm b. annelid c. roundworm d. echinoderm

The option which is an unsegmented acoelomate worm is flatworm. The correct answer is the first option. The other types of worms are all either segmented, or not considered to be acoelomate, which makes the first option the correct one, given that it falls under both of these categories.

The three states of matter are solids, liquids, and gases. Sometimes, in extreme environments, there is plasma.