Answer :
Answer: B) Invertebrates that lack a true body cavity and have a body composed mainly of a simple, undifferentiated protoplasm.
Explanation: Protoplasmic invertebrates, such as members of the phylum Protozoa, have simple, undifferentiated bodies without a true body cavity. They rely on protoplasm for all essential functions.
Here’s why the other options are incorrect:
A) Invertebrates with a complex body structure and specialized organs for various functions: This describes more complex invertebrates, such as those in the phylum Annelida (earthworms) or Arthropoda (insects), which have specialized organs and body systems.
C) Invertebrates with a segmented body and a well-developed nervous system: This description fits segmented invertebrates like those in the phylum Annelida and some members of Arthropoda, which have a segmented body and a more complex nervous system.
D) Invertebrates with a hard external skeleton and jointed limbs: This applies to arthropods, such as insects and crustaceans, which have exoskeletons and jointed limbs.
