- Dead organisms are a kind of waste
- Dead organisms are the source of nutrients for decomposers
- Therefore, waste is a source of nutrients for decomposers

- Waste is a source of nutrients for decomposers
- If an object is a source of something for something else then that something else can obtain that something from that object
- Therefore, decomposers obtain nutrients from waste

- Decomposers obtain nutrients from waste
- Eating / digestion is when an organism takes in nutrients from food into itself by eating
- Hence, decomposers obtain nutrients by eating waste

- Decomposers obtain nutrients by eating waste
- Eating is a kind of method for consuming
- Therefore, decomposers obtain nutrients by consuming waste

- Decomposers obtain nutrients by consuming waste
- A decomposer is a kind of living thing
- Hence, a decomposer is a kind of living thing that obtains nutrients by consuming waste

- A decomposer is a kind of living thing that obtains nutrients by consuming waste
- Classifying is when one sorts something by kind / type
- Therefore, a living thing that obtains nutrients by consuming waste can be classified as a decomposer

Therefore, a living thing that obtains nutrients by consuming waste can be classified as a decomposer
Question
Organisms that consume wastes to obtain the nutrients they need to survive are classified as

Context
- A decomposer is a kind of living thing 
- If an object is a source of something for something else then that something else can obtain that something from that object 
- Eating / digestion is when an organism takes in nutrients from food into itself by eating 
- Eating is a kind of method for consuming 
- Classifying is when one sorts something by kind / type 
- Dead organisms are a kind of waste 
- Dead organisms are the source of nutrients for decomposers