is the only effective way invertebrates fight disease

Excretion is the only effective way that invertebrates fight off diseases. Most of the aquatic invertebrates get rid of toxins within their body by the process of diffusion. Ammonia is usually the secreted product that leaves the surface of the body of aquatic invertebrates. This type of behavior enables vertebrates to maintain homeostasis within their bodies and to help them adapt to their specific environments.

4 is the GCF because they it devides equally into both of them