Step 1: Understanding the Concept:
Cereal grains contain various storage proteins classified based on their solubility properties into albumins, globulins, prolamins, and glutelins.
Different cereal crops have characteristic dominant proteins.
Step 3: Detailed Explanation:
- Gliadin (D): The prolamin protein characteristic of wheat.
- Zein (C): The prolamin protein characteristic of maize.
- Hordenin (A): The prolamin protein characteristic of barley.
- Oat proteins: Oats are unique among cereals as their major storage protein group is globulins (avenalins, making up about 70-80% of the total protein). However, oats also contain a significant portion of glutelins.
Among the given choices, "Glutelins" is the closest and most representative match for oat protein composition as globulin is not listed.
Therefore, by excluding the specific proteins of barley (Hordenin), maize (Zein), and wheat (Gliadin), we select Glutelins.
Step 4: Final Answer:
The correct option is (B).