Question: Seaford railway station, Adelaide is in what suburb within the city of  Onkaparinga.

Context paragraphs:
Willunga railway line: The Willunga railway line ran through the southern Adelaide suburbs from Adelaide railway station to Willunga, over 45 km long (longer than the current Gawler line, 42.2 km ).  The line was opened in Willunga by the Governor of South Australia Sir Henry Galway on 20 January 1915, and initially had 16 stopping places between Adelaide and Willunga.  It closed beyond Hallett Cove in 1969 and was dismantled in 1972.  The Seaford railway line continues from Hallett Cove along a different alignment before rejoining the route of the old line between Seaford Road and Griffiths Drive.

Seaford railway station, Melbourne: Seaford railway station is located on the Frankston line in Victoria, Australia.  It serves the south-eastern Melbourne suburb of Seaford opening on 1 December 1913.  A substation is situated at the northern end of the station.

Seaford Meadows railway station: Seaford Meadows railway station is located on the Seaford line.  Situated in the southern Adelaide suburb of Seaford Meadows, it is 34.7 kilometres from Adelaide station.

Moana, South Australia: Moana is an outer coastal suburb in the south of Adelaide, South Australia.  The suburb is approximately 36.4 km from the Adelaide city centre.  It lies within the City of Onkaparinga local government area, and neighbours the suburbs Seaford, Maslin Beach, Seaford Rise and Port Noarlunga

Emerson Crossing: Emerson Crossing, the 'South Road Overpass' or simply 'the Overpass' are the informal names given to the intersection of South Road, Cross Road and the Seaford railway line in Adelaide, South Australia.  South Road crosses north-south over both Cross Road and the diagonal railway via a large bridge built in the early 1980s.  This was done in an attempt to cater for the ever increasing amount of traffic which went through the intersection and was constantly congested during peak hour times.  Emerson Railway Station is located in the north eastern corner of the crossing.  The train station and crossing are both named after Emerson Street, a small dead end road just north of the intersection along South Road, in the suburb of Black Forest.

Goodwood railway station: Goodwood railway station is the junction station for the Belair and Seaford/Tonsley lines.  The Belair line diverges south-east towards Millswood, while the Seaford and Tonsley lines diverge south-west towards Clarence Park.  The Glenelg Tram line crosses over the railway lines at the south end of Goodwood station.  The station services the Adelaide inner-southern suburb of Goodwood, and is 5.0 km from Adelaide station.

Seaford railway station, Adelaide: Seaford railway station is the terminus of the Seaford line.  Situated in the southern Adelaide suburb of Seaford, it is 35.9 kilometres from Adelaide station.

Marino Rocks Greenway: The Marino Rocks Greenway is a 15 km cycling route in Adelaide, South Australia.  It follows the Seaford railway line from the southwestern corner of the Adelaide city centre to Marino Rocks railway station.  The route leads into the Coast to Vines Rail Trail which continues along the alignment of the former Willunga railway line.

Seaford (Sussex) railway station: Seaford Railway Station is in Seaford, East Sussex, England.  It is the terminus of the Seaford Branch Line of the East Coastway Line.  The station has been reduced to single track and only one platform remains in use (previously two).  The remaining platform is still referred to as 'Platform 2'.  Train services from the station are provided by Southern.

Seaford, South Australia: Seaford is a metropolitan suburb of Adelaide, South Australia.  It lies within the City of Onkaparinga.  Seaford railway station is the southern terminus of the Seaford railway line from Adelaide railway station.

Supporting paragraphs: Seaford railway station, Adelaide Seaford, South Australia
Answer: Seaford