Concept:Devolution is the constitutional or legal transfer of powers from the central government to lower levels of government.
Explanation:The key phrase in the question is a transfer made through a constitutional or legislative process.
All the options involve moving authority from the centre downward, but they differ in method and effect.
Delegation is merely an administrative transfer that the central government can revoke at any time.
Deconcentration only spreads central offices and officials to the regions without giving them real powers.
Decentralisation is the broad general term that covers both deconcentration and devolution.
Devolution, however, specifically grants powers and functions to the lowest levels of government by law or constitution.
This makes the lower governments legally autonomous in the areas assigned to them.
Since the question stresses a constitutional or legislative process, the definition fits devolution exactly.
Answer:B. Devolution