Prostomes are mollusca, annelids and arthropods while deuterostomes are echinoderms, hemichordates and chordates So correct answer is prostomes and bilaterally symmetrical (D) Solution Prostomes are mollusca, annelids and arthropods while deuterostomes are echinoderms, hemichordates and chordates So correct answer is prostomes and bilaterally symmetrical (D).