Which term describes the united kingdom’s process of returning the delegation of authority from the central government back to the regional governments of scotland, wales, and northern ireland?
a. devaluation
b. coalition
c. federation
d. devolution

The term that best describes the United Kingdom’s process of returning the delegation of authority from the central government back to the regional governments of Scotland, Wales, and Northern Ireland would be "devolution," since this is the opposite of a transfer of power to a higher level. 

Cwould be the answer