Organisms that get their energy by eating other organisms are called
a. producers.
b. consumers.
c. predators.
d. prey.

Consumers. 
Producers make the energy themselves (like plants) - if I remember correctly.
Prey are the hunted organisms. 
Predators are like hunters who eat other organisms but the correct terminology used in food chains is usually consumers - primary and secondary etc. (again if I remember correctly).

Consumers as they consume generally producers

Through photosynthesis, certain organisms convert solar energy (sunlight) into chemical energy, which is then used to build carbohydrate molecules. The energy used to hold these molecules together is released when an organism breaks down food. Cells then use this energy to perform work, such as cellular respiration.

Explanation: