The English cities of Gloucester and Worcester are on which river?

Option D

Gloucestershire, administrative, geographic, and historic county of southwestern England. It lies at the head of the River Severn estuary on the border with Wales. The administrative, geographic, and historic counties cover somewhat different areas. The administrative county comprises six districts: Cotswold, Forest of Dean, Stroud, the boroughs of Cheltenham and Tewkesbury, and the city of Gloucester, the county seat.

 In the northern and northeastern parts of the geographic county, the following villages, and surrounding areas, belong to the historic county of Worcestershire: Daylesford, Evenlode, Aston Magna, Blockley, Paxford, Cutsdean, Teddington, Chaceley, Staunton, and Redmarley D’Abitot. The historic county of Gloucestershire, however, includes the following areas outside the geographic county: