Which region does the license plate 'Dong' belong to?

[DeAutumn]

Currently, there is no license plate with the prefix 'Dong'. The first character of a license plate is a Chinese character, representing the provincial-level administrative region where the vehicle is registered, which is the abbreviation of the province, municipality, or autonomous region. The second character of a license plate is an English letter, indicating the prefecture-level administrative region where the vehicle is registered, corresponding to the letter code of the prefecture-level city, district, autonomous prefecture, or league. A license plate serves as an identification number for a vehicle, much like an ID card does for a person. For automobiles, the license plate number is structured in two rows: the upper row is the vehicle registration authority code, and the lower row is the license plate number. For motorcycles, the license plate number is arranged horizontally, with the vehicle registration authority code on the left and the license plate number on the right.