Answer the following question given this paragraph: 

Organ systems are organized into the organism. The different organ systems work together to carry out all the life functions of the individual. For example, cardiovascular and respiratory systems work together to provide the individual with oxygen and rid it of carbon dioxide.


Q: The different types of what systems work together to carry out all the life functions of the individual?

 Choices:

- maturation systems

- digestive systems

- heartbeat systems

- organ systems

A:
organ systems
