Final answer:
The segments of the small intestine through which food travels in order are the duodenum, jejunum, and ileum. The duodenum starts the digestion process, followed by the jejunum which absorbs nutrients, and ending with the ileum.
Step-by-step explanation:
The correct order in which food travels through the segments of the small intestine is a) Duodenum, jejunum, ileum. The duodenum is the first region adjacent to the stomach where most chemical digestion takes place. Next, the jejunum follows where the majority of nutrient absorption into the blood occurs. Lastly, the ileum is the final segment of the small intestine. There is no clear demarcation between the jejunum and the ileum, but collectively these regions are crucial for the digestion and absorption processes of our food intake.