Which of the following statements about the gastrointestinal system are TRUE?

A) After nutrient absorption, blood returns directly to the heart for recirculation.
B) The duodenum and ileum make up the bulk of the small intestine.
C) The blood absorbs nutrients ingested through the gastrointestinal tract.
D) Mechanical digestion takes place in the duodenum, jejunum, and ileum.

C