Question: The Southern Railway runs from Vienna to Graz and the border with Slovenia at Spielfeld via the first mountain railway built in Europe to use what kind of track?

Context paragraphs:
Semmering railway: The Semmering railway (German: "Semmeringbahn" ) in Austria, which starts at Gloggnitz and leads over the Semmering to Mürzzuschlag was the first mountain railway in Europe built with a standard gauge track.  It is commonly referred to as the world's first true mountain railway, given the very difficult terrain and the considerable altitude difference that was mastered during its construction.  It is still fully functional as a part of the Southern Railway which is operated by the Austrian Federal Railways.

Most–Moldava railway: The Most–Moldava railway is a branch line in Czech Republic, which was originally built and operated by the Prague-Dux Railway.  The line, formerly known as the"Teplitz Semmering Railway" ("Teplitzer Semmeringbahn") runs from Most ("Brüx") over the Ore Mountains to Moldava ("Moldau") and used to have a junction with the Nossen-Moldau railway there in Saxony until 1945.  In the Czech Republic the line is known today as the "Moldavská horská dráha" ("Moldau Mountain Railway") or "Krušnohorská železnice" ("Ore Mountain Railway").

Southern Railway (Austria): The Southern Railway (German: "Südbahn" ) is a railway in Austria that runs from Vienna to Graz and the border with Slovenia at Spielfeld via Semmering and Bruck an der Mur.  It was originally built by the Austrian Southern Railway company and ran to Ljubljana and Trieste, the main seaport of the Austro-Hungarian Monarchy.  The twin-track, electrified section that runs through the current territory of Austria is owned and operated by Austrian Federal Railways (ÖBB) and is one of the major lines in the country.

Rudyard Lake Steam Railway: The Rudyard Lake Steam Railway is a ridable miniature railway and the third railway of any gauge to run along the side of Rudyard Lake in Staffordshire.  The railway runs for 1+1/2 mi on the track bed of an old standard gauge North Staffordshire Railway line.  After the NSR line closed down, a small narrow gauge train ran on the site for two years before moving via Suffolk to Trago Mills in Devon.  The current line started in 1985 and is gauge, and operates to a timetable.  It was built by Peter Hanton of Congleton working on his own over a period of 10 years.  He sold the railway to the Rudyard Lake Steam Railway Ltd in October 2000 who have developed it since that date.

Carolina and Northwestern Railway: The Carolina & Northwestern Railway (Ca&NW) was a railroad that served South Carolina and North Carolina from 1897 until January 1, 1974.  The original line was operated by the Ca&NW as a separate railroad controlled by the Southern Railway until 1974 when the name was changed to the Norfolk Southern Railway.  On June 1, 1982, Southern Railway and Norfolk and Western Railroad merged to form Norfolk Southern Railway.  Choosing to use the name 'Norfolk Southern Railway' for the merger, in 1981, the original Ca&NW line along with original Norfolk Southern Railway was renamed Carolina and Northwestern once again.  In the early 1950s several shortline subsidiaries of the Southern Railway were leased to the Ca&NW for operation, with these lines remaining a part of the Ca&NW into the 1980s.

D. William Brosnan: D. William Brosnan was a president of Southern Railway in the USA, a railroad that later merged with Norfolk and Western Railroad to form Norfolk Southern Railway.  Born in 1903 in Albany, Georgia, he was the son of the town's fire chief.  In 1923, he took a job as an engineer with the Georgia Department of Highways, before taking a job at as an apprentice student engineer for the Southern Railway, three years later, maintaining the right-of-way.  Between 1931 and 1952, he had several promotions, from apprentice student engineer to junior engineer, to division superintendent, to general manager of the Central Lines of the Southern Railway, to vice president of operations.  During his time as chief engineer for the Western Lines of the Southern Railway, in 1945 and 1946, he oversaw an increased mechanization of track maintenance and construction on the Southern Railway, and during his time as general manager for the Central Lines, he oversaw the automation of freight car classification in yards and terminals.  He succeeded Harry A. deButts in 1962.  In 1964 Brosnan was selected as the first recipient of the Man of the Year award by "Modern Railways" magazine, an award now presented by "Railway Age" magazine as the Railroader of the Year.

Hakone Tozan Railway: The Hakone Tozan Railway (箱根登山鉄道 , Hakone Tozan Tetsudō ) is a private railway company in Japan, part of the Odakyu Group.  It is best known for its operation of the Hakone Tozan Line, the first mountain railway in Japan, but like most Japanese railway companies, also operates bus service, namely Hakone Tozan Bus.  It also operates the connecting Hakone Tozan Cable Car.

Green Mountain Cog Railway: The Green Mountain Cog Railway was a mountain railway built to carry tourists to the top of Green Mountain (now known as Cadillac Mountain) on Mount Desert Island in Maine.  Its track was built to gauge, which is technically a narrow gauge, as it is a ⁄ -inch less than .

East Siberian Railway: The East Siberian Railway ("Восточно-Сибирская железная дорога" ) is a railway in Russia (a branch of the Russian Railways and a part of the Trans-Siberian Railway), which runs across Irkutsk Oblast, Chita Oblast, Buryatia, and Yakutia.  The railway administration is located in Irkutsk.  The East Siberian Railway borders with the Krasnoyarsk Railway (railway station of Yurty), Trans-Baikal Railway (railway station of Petrovsky Zavod), and Baikal Amur Mainline (railway station of Lena-Vostochnaya).  To the south, the East Siberian Railway runs close to the Russo-Mongolian border (railway station of Naushki).  As of 2008, the total working length of the East Siberian Railway was 3848.1 km ; number of employees – 46,233 (61,418 in 2005); net weight hauled – 76 million tonnes (75.934 million in 2005); long-distance passenger traffic – 3.6 million people (4.838 million in 2005); suburban traffic – 29 million people (26.225 million in 2005).  Annual cargo turnover is 278 million tonnes.

Reisseck Railway: The Reisseck Railway (sometimes Reißeck Railway, German: "Reißeckbahn" ) is a mountain railway, that runs from Carinthia's Möll valley into the Reißeck Group, a small mountain range in southern Austria.  It comprises the Reisseck Funicular and the Reisseck Mountain Railway (a narrow gauge railway).

Supporting paragraphs: Southern Railway (Austria) Semmering railway
Answer: standard gauge track