Question: Brighton railway station is located on what kind of line?

Context paragraphs:
Seaford railway line: The Seaford railway line is a suburban commuter line in Adelaide, South Australia.

North Brighton railway station: North Brighton railway station is located on the Sandringham line in Victoria, Australia.  It serves the south-eastern Melbourne suburb of Brighton, opening as Bay Street on 19 September 1859, renamed North Brighton on 1 January 1867, Brighton on 1 December 1908, and back to North Brighton on 1 January 1920.

Burgess Hill railway station: Burgess Hill railway station serves Burgess Hill in West Sussex, England.  Located on the Brighton Main Line and Thameslink 9+1/4 mi north of Brighton railway station, train services are provided by Southern and Thameslink.  Northern Burgess Hill is served by Wivelsfield railway station.

Brighton railway station: Brighton railway station is the southern terminus of the Brighton Main Line in England, and the principal station serving the city of Brighton and Hove, East Sussex.  It is 50  49  (81.4529232 round 2  km) down-line from ; the preceding station is .

Melbourne and Suburban Railway Company: The Melbourne and Suburban Railway Company was a railway company in Victoria, Australia.  The company opened a line from Princes Bridge railway station in Melbourne, Australia to Punt Road (Richmond) and South Yarra (then called Gardiners Creek Road) in 1859, Prahran in 1859 and Windsor in 1860, connecting with the St Kilda and Brighton Railway Company's line from St Kilda to Bay Street (now North Brighton) in 1859 and Beach Station (now Brighton Beach) in 1861.

New Brighton railway station: New Brighton railway station is situated in New Brighton, Wirral, England.  It is situated at the end of the New Brighton branch of the Wirral Line 8.25 mi west of Liverpool Lime Street on the Merseyrail network.

Brighton railway station, Adelaide: Brighton railway station is located on the Seaford line.  Situated in the south-western Adelaide suburb of Brighton, it is 16 kilometres from Adelaide station.

London Bridge – Greenwich Railway Viaduct: The London Bridge – Greenwich Railway Viaduct consists of a series of nineteen brick railway viaducts linked by road bridges between London Bridge railway station and Deptford Creek, which together make a single structure 3.45 mi in length.  The structure carries the former London and Greenwich Railway line and consists of 851 semi-circular arches and 27 skew arches or road bridges.  It is the longest run of arches in Britain, It is also one of the oldest railway viaducts in the world, and the earliest example of an entirely elevated railway line.  It was built between 1834 and 1836.  The original viaduct had been widened for 1.95 mi of its length between Corbett's Lane and London Bridge on the south side to accommodate the trains of the London and Croydon Railway and London and Brighton Railway, in 1842 and also for 2.65 mi on the north side to accommodate the South Eastern Railway main line in 1850.  It is a Grade II listed structure.

South Brighton railway station, Adelaide: South Brighton railway station is a former railway station on the Seaford line in Adelaide, South Australia.  It was located about 15.8 kilometres from Adelaide station.  The station closed in 1976, and was demolished shortly after, A newer station was built 200 metres to the south of that station in the same year.  The old subway that went below the old station was in use until the early 1990s, but has now been filled in and replaced with a ground level passenger walkway.  Adjacent to the old station is a disused delicatessan (now residential) building that served the station's passengers, and then the local population until the early 1990s.

Middle Brighton railway station: Middle Brighton railway station is located on the Sandringham line in Victoria, Australia, and serves the south-eastern Melbourne suburb of Brighton.  It opened, with the name "Church Street", on 21 September 1861, and was renamed "Middle Brighton" on 1 January 1867.

Supporting paragraphs: Brighton railway station, Adelaide Seaford railway line
Answer: a suburban commuter line