You are presented with the question "What does an animal like a mollusk lack that many other animals have?" and the following answer choices: 
- sensory neurons
 - Energy.
 - Bodily water
 - kinetic energy
 - alveoli
 - the skin
 - an organism's body
 - spinal column

Now knowing that mollusks are invertebrates such as the common snail and invertebrates are animals who lack a backbone or spinal column, choose the best answer.


 

        spinal column 