Concept:In the shown farm animal, the part labelled II is the proventriculus, which is the region where protein digestion begins.
Explanation:The diagram represents the digestive tract of a bird-like farm animal.
The proventriculus is a glandular stomach that secretes hydrochloric acid and the enzyme pepsin.
Pepsin acts on proteins to break them down into peptides.
Therefore, protein digestion starts in the proventriculus.
Among the labelled parts, label II points to the proventriculus.
The other labels indicate different parts of the digestive tract where protein digestion does not start.
So the correct labelled part is II.
Answer:B. II
