Question: What battle tank was acquired from Germany by the Polish army, developed by Krauss-Maffei?
Context: The Stingray is a light tank produced by Textron Marine & Land Systems division (formerly Cadillac Gage).  It was specifically designed to use as many existing components of other American armored fighting vehicles as possible to keep costs down.  It was originally developed for the U.S. Army as a light tank—with firepower matching that of a main battle tank (MBT), while lacking the countermeasures to be considered a main battle tank—for the U.S. Army's Armored Gun System competition in the 1980s.  It was exported for use by armed forces of Thailand, who remains the only user. The Lince (] , meaning "Lynx") was a Spanish development programme for a proposed main battle tank that unfolded during the late 1980s and early 1990s.  The intention was to replace the M47 and M48 Patton tanks that the Spanish Army had received under the U.S. Mutual Defense Assistance Act between 1954 and 1975, and to complement the AMX-30E tanks manufactured for the army during the 1970s.  Companies from several nations, such as German Krauss-Maffei, Spanish Santa Bárbara, and French GIAT, made bids for the development contract.  The main priorities were mobility and firepower, with secondary priority placed on protection; the Lince tank was to have been lighter and faster than its competitors.  The vehicle's size would also have been restricted by the Spanish rail and highway network.  To achieve a sufficient level of firepower and protection, given the size requirements, the Lince was to use Rheinmetall's 120 mm L/44 tank-gun and German composite armour from the Leopard 2A4. The Leopard 2 is a main battle tank developed by Krauss-Maffei in the 1970s for the West German Army.  The tank first entered service in 1979 and succeeded the earlier Leopard 1 as the main battle tank of the German Army.  Various versions have served in the armed forces of Germany and 12 other European countries, as well as several non-European nations, including Canada (Leopard 2A4m can), Chile, Indonesia, Singapore and Turkey.  The Leopard 2 was used in Kosovo with the German Army and has also seen action in Afghanistan with the Danish and Canadian contributions to the International Security Assistance Force, as well as seeing action in Syria with the Turkish Armed Forces against IS and the YPJ. The TR-85 is a main battle tank designed for the armed forces of Romania.  Based on the TR-77-580 (Romanian-built version of the Soviet T-55 tank), the TR-85 tank was developed from 1978 to 1985 and produced from 1986 until 1990.  A modernization program was initiated in March 1994 in order to upgrade the TR-85 tanks to NATO standards.  The result was the TR-85M1 main battle tank, currently the most modern tank in service with the Romanian Land Forces.  Although a further development of the T-55, the TR-85M1 uses a T-block powerpack (similar to the one used in the Leopard 1) based on a V8 German 830 hp diesel engine, an improved turret, a locally-designed "Ciclop" fire control system (with cross-wind sensor, laser rangefinder and night vision), new 100 mm BM-412 Sg APFSDS-T projectiles and a completely redesigned suspension with 6 road wheels on each side, protected by metal side skirts.  Combat weight is 50 tons. The Polish Legions (Polish: "Legiony Polskie" ) was a name of the Polish military force (the first active Polish army in generations) established in August 1914 in Galicia soon after World War I erupted between the opposing alliances of the Triple Entente on one side (including the British Empire, the French Republic and the Russian Empire); and the Central Powers on the other side, including the German Empire and Austria-Hungary.  The Legions became "a founding myth for the creation of modern Poland" in spite of their considerably short existence; they were replaced by the Polish Auxiliary Corps (Polish: "Polski Korpus Posiłkowy" ) formation on 20 September 1916, merged with Polish II Corps in Russia on 19 February 1918 for the Battle of Rarańcza against Austria-Hungary, and disbanded following the military defeat at the Battle of Kaniów in May 1918, against imperial Germany.  General Haller escaped to France to form the Polish army in the West against the anti-Polish German-Bolshevik treaty. A main battle tank (MBT), also known as a battle tank or universal tank, is a tank that fills the armor-protected direct fire and maneuver role of many modern armies.  Cold War-era development of more powerful engines, better suspension systems and lightweight composite armour allowed a tank to have the firepower of a super-heavy tank, armor protection of a heavy tank, and mobility of a light tank all in a package with the weight of a medium tank.  Through the 1960s, the MBT replaced almost all other tanks, leaving only some specialist roles to be filled by lighter designs or other types of armoured fighting vehicles. The M48 Patton is a main battle tank (MBT) that was designed in the United States.  It was the third tank to be officially named after General George S. Patton, commander of the U.S. Third Army during World War II and one of the earliest American advocates for the use of tanks in battle.  It was a further development of the M47 Patton tank.  The M48 Patton was in U.S. service until replaced by the M60 and served as the U.S. Army and Marine Corps's primary battle tank in South Vietnam during the Vietnam War.  It was widely used by U.S. Cold War allies, especially other NATO countries. The CM-11 Brave Tiger (勇虎式戰車) is a Main Battle Tank (MBT) that was developed by the American General Dynamics and the Republic of China Army (ROCA) Armored Vehicle Development Center It was introduced to the public on 14 April 1990.  Being a variant of the M48 Patton, it is also known as the M48H Main Battle Tank.  The Ministry of National Defence is now acquiring the M1A1 Abrams to supplement the CM-11. The PT-91 "Twardy" ("resilient") is a Polish main battle tank.  A development of the T-72M1, it first entered service in 1995.  The PT-91 was designed at the OBRUM ("OBRUM" for "Ośrodek Badawczo-Rozwojowy Urządzeń Mechanicznych" – Polish for "Research and Development Centre for Mechanical Appliances") and is produced by the Bumar Łabędy company, a part of the Bumar Group, a Polish technical military consortium.  Changes from the T-72 include a new dual-axis stabilized fire-control system, reactive armour, a more powerful engine, transmission and new automatic loader.  Unlike many other T-72 upgrades, the Polish Army PT-91s are upgraded using elements created almost exclusively by domestic companies, including a new engine, the fire control system and all communication system elements.  Many of those elements were used to upgrade existing fleets of T-72 tanks in countries including the Czech Republic (T-72M4 CZ), Georgia (T-72SIM-1) and India (T-72 Ajeya Mk.  2). The Polish military continues to use some Soviet-era equipment; however, since joining NATO in 1999, Poland has been upgrading and modernizing its hardware to NATO standards.  The General Staff has been reorganized into a NATO-compatible J/G-1 through J/G-6 structure.  Recent modernization projects include the acquisition of (48) F-16 fighter jets from the United States, (256) Leopard 2 MBTs from Germany, ATGM technology from Israel (as well as possible future acquisition of Rafael Python 5 missiles), and (957) Patria AMV AFVs from Finland.
Answer: Leopard 2