Answer the following question given this paragraph: 

Food allergies are like other allergies. They occur when the immune system reacts to harmless substances as though they were harmful. Almost ten percent of children have food allergies. Some of the foods most likely to cause allergies are shown below ( Figure below ).


Q: The reaction of which body system causes food allergies?

 Choices:

- cardiac system

- lymphatic system

- nervous system

- immune system

A:
immune system
