Ribbon-like acoelomates with bilateral symmetry are examples of

cnidarians: jellyfish
platyhelminthes: flat worms
nemotoda: round worms
mollusca: mollusks
annelida: segmented worms

The correct answer is platyhelminthes: flatworms.

Explanation:

Platyhelminthes are generally known as tapeworms or flatworms, these species are ribbon-like and are soft-bodied invertebrates. Some of the species of this phylum live as parasites in animals and human beings. The most distinguishing characteristic of these invertebrates is their flat and ribbon-like appearance.  

Some of the characteristics of Platyhelminthes are that their body is dorsoventrally flattened, they show radial symmetry, they do not possess a body cavity and thus are known as acoelomate, they are triploblastic comprising three germ layers, and their body is soft and unsegmented.  

answer; ///the correct answer to the above question is (

the answer to your question is:

c. complementary base-pairing