The digestive system absorbs nutrients which are transported by the nervous system. The digestive system absorbs nutrients which are transported by the circulatory system. The circulatory system exchanges gases which are transported by the nervous system. The circulatory system exchanges gases which are transported by the digestive system.
I gave my students this multiple choice question: Which statement correctly describes a relationship between two human body systems?

Only one answer is correct among these 4 choices:
- The digestive system absorbs nutrients which are transported by the nervous system.
- The digestive system absorbs nutrients which are transported by the circulatory system.
- The circulatory system exchanges gases which are transported by the nervous system.
- The circulatory system exchanges gases which are transported by the digestive system.

Could you tell me which one is correct?

The digestive system absorbs nutrients which are transported by the circulatory system.