Question: Which town lies between Frogmore and St Albans in Hertfordshire, just inside the M25 motorway that circles London?

Context paragraphs:
St Albans Abbey railway station: St Albans Abbey railway station in St Albans, Hertfordshire, England is about 0.6 mi south of the city centre in the St Stephen's area.  It is the terminus of the Abbey Line from Watford Junction, part of the London Midland franchise.  It is one of two stations in St Albans, the other being the much larger and busier St Albans City.

St Albans: St Albans , is a city in Hertfordshire, England, and the major urban area in the City and District of St Albans.  It lies east of Hemel Hempstead and west of Hatfield, about 19 mi north-northwest of central London, 8 mi southwest of Welwyn Garden City and 11 mi south-southeast of Luton.  St Albans was the first major town on the old Roman road of Watling Street for travellers heading north, and it became the Roman city of Verulamium.  It is a historic market town and is now a dormitory town within the London commuter belt and the Greater London Built-up Area.

Frogmore, Hertfordshire: Frogmore is a village 3 mi north of Radlett in Hertfordshire, and 2 mi south of St Albans.  It is located in St Stephen civil parish, in St Albans District, in the county of Hertfordshire.

St Albans City railway station: St Albans City railway station, also shortened to St Albans, is one of two railway stations in St Albans, Hertfordshire, England, the other being St Albans Abbey railway station.  City station is the more important of the two stations, as it serves London, Gatwick Airport, Luton Airport and Brighton.  It is located 0.5 mi east of the city centre, on the Midland Main Line and served by Thameslink trains on the Thameslink route.

Radlett: Radlett is an affluent town in the county of Hertfordshire between St Albans and Borehamwood on Watling Street with a population of approximately 8,000.  It is located in the council district of Hertsmere and is covered by two wards, Aldenham East and Aldenham West.  It is located inside the M25 motorway.

St Stephen, Hertfordshire: St Stephen is a civil parish in the St Albans City and District in Hertfordshire, England.  It is located approximately 17 mi north-northwest of central London, straddling the M25 motorway and immediately adjacent to the southern boundary of St Albans.  St Stephen is a partly urbanised parish with multiple centres of activity and open land that forms part of the Metropolitan Green Belt.  The local council is St Stephen Parish Council.  The parish covers Bricket Wood, Chiswell Green, Frogmore, How Wood and Park Street.  It is an ancient parish, and sections of it were transferred to St Albans progressively up to 1935.  At the 2011 census it had a population of 13,865.

St Albans School, Hertfordshire: St Albans School is an independent school in the city of St Albans in Hertfordshire, in the South East of England.  Entry before Sixth Form is for boys only, but the Sixth Form has been co-educational since 1991.  Founded in 948 by Wulsin, St Albans School is not only the oldest school in Hertfordshire but also one of the oldest in the world.  The school has been called "Britain's oldest public school" by the "Daily Mail".  Nicholas Carlisle, in 1818, described the school as "of very ancient origin, and of great celebrity" and the "Good Schools Guide" describes St Albans as a "traditional public school, with a rich history".

Hatfield and St Albans Railway: The Hatfield & St Albans Railway was a branch of the Great Northern Railway which connected the Hertfordshire towns of St Albans and Hatfield.  It opened in 1865 with the principal aim of allowing St Albans traffic to access the Great Northern's main line to London at , but soon came into difficulties when the Midland Railway inaugurated a direct route to London through St Albans.  Passenger receipts declined in the 1930s, resulting in the temporary withdrawal of services in 1939.  Passenger services were permanently withdrawn in 1951, leaving goods traffic to linger on until December 1968.  Much of the route of the line is now incorporated into the Alban Way, a footpath and cycleway.

Abbey line: The Abbey line, also called the St Albans Abbey branch line, is a railway line from Watford Junction to St Albans Abbey.  The 6.5 mi route passes through town and countryside in the county of Hertfordshire, just outside the boundaries of the Oyster Card and London fare zones.  Its northern terminus in St Albans Abbey is located in the south of the city, around 1.2 km away from the larger St Albans City railway station on the Thameslink line.

Dean of St Albans: The Dean of St Albans is the head of the Chapter of St Albans Cathedral in the city of St Albans, England in the Diocese of St Albans.  As the Dean of St Albans is also the Rector of St Albans, with parochial responsibilities for the largest parish in the Church of England, it is regarded as one of the most senior Deaneries in the United Kingdom.

Supporting paragraphs: Frogmore, Hertfordshire Radlett
Answer: Radlett