They are considered so because are the indispensable parts of the nature cycle.Without formation,decay cannot be possible and similarly,formation cannot be possible without decay.In addition to this,THEY ARE IN A CHRONOLOGICAL MANNER SET BY NATURE and that's why cannot be seperated and so together constitute the cycle of nature.
Answer:
A. Duodenum
Explanation:
Duodenum is the first part of the small intestine which receives bile juice, pancreatic and intestinal digestive juices. The digestive enzymes present in these juices completes the process of digestion.
The lining of the duodenum has numerous finger-like projections called intestinal villi. The villi are specialized to absorb the digested food by providing increased surface area for the process of digestion. Hence, among the given options, the absorption of digested food occurs in duodenum.