Fact 1: Mollusks are a major food source for other organisms, including humans.

Fact 2: Mollusks are invertebrates and are no exception.

Given the two facts above, answer the question "What is a major food source for humans?" with the following options: 
- poison dart frogs
 - honeybees
 - barnacles
 - intervertebrates
 - other humans
 - photosynthesis
 - the body's largest organ
 - Most plants


 

    intervertebrates     