Question: The M2 light tank, officially Light Tank, M2, was an American pre-World War II light tank, the most common model, the M2A4, was equipped with one 37 mm M5 gun and five of which .30 caliber medium machine gun that was widely used during the 20th century, especially during World War II, the Korean War, and the Vietnam War?
Context: The Type 98 light tank Ke-Ni (九八式軽戦車 ケニ , Kyuhachi-shiki keisensha Ke-Ni ) or Type 98A Ke-Ni Ko (also known as Type 98 Chi-Ni light tank) was designed to replace the Imperial Japanese Army's Type 95 Ha-Go light tank, Japan's most numerous armored fighting vehicle during World War II.  Although designed before World War II, production did not start until 1942, with 104 being produced by the end of the war. The Marmon-Herrington Combat Tank Light Series were a series of American light tanks/tankettes that were produced for the export market at the start of the Second World War.  The CTL-3 had a crew of two and was armed with two .30 cal (7.62 mm) M1919 machine guns and one .50 cal (12.7 mm) M2 Browning machine gun.  They were originally designed to be amphibious light tanks.  They were rejected by the U.S. Marine Corps in 1939, but after the attack on Pearl Harbor they were exported and used as an emergency light tank. The M24 Chaffee, officially Light Tank, M24, is an American light tank used during the later part of World War II and in postwar conflicts including the Korean War and, with the French, in the War in Algeria and the First Indochina War.  In British service it was given the service name Chaffee after the United States Army General Adna R. Chaffee, Jr., who helped develop the use of tanks in the United States armed forces.  While long removed from American and British service, it is still found in service as a light tank in third-world countries, along with other hardware from that era. The T-70 was a light tank used by the Red Army during World War II, replacing both the T-60 scout tank for reconnaissance and the T-50 light infantry tank for infantry support.  The T-80 light tank was a more advanced version of the T-70 with a two-man turret—it was produced only in very small numbers when light tank production was abandoned.  The T-90 self-propelled anti-aircraft gun was a prototype vehicle with twin machine guns, based on the T-70 chassis. The M1 Combat Car, officially Light Tank, M1, was a light tank used by the U.S. Cavalry in the late 1930s and developed at the same time as the infantry's very similar M2 light tank.  After the Spanish Civil War, most armies, including the U.S. Army, realized that they needed tanks armed with cannons, not merely vehicles armed with machine guns, and so the M1 became obsolete. The M22 Locust, officially Light Tank (Airborne), M22, was an American-designed airborne light tank which was produced during World War II.  The Locust began development in 1941 after the British War Office requested that the American government design a purpose-built airborne light tank which could be transported by glider into battle to support British airborne forces.  The War Office had originally selected the Light Tank Mark VII Tetrarch light tank for use by the airborne forces, but it had not been designed with that exact purpose in mind so the War Office believed that a purpose-built tank would be required to replace it.  The United States Ordnance Department was asked to produce this replacement, which in turn selected Marmon-Herrington to design and build a prototype airborne tank in May 1941.  The prototype was designated the Light Tank T9 (Airborne), and was designed so that it could be transported underneath a Douglas C-54 Skymaster transport aircraft, although its dimensions also allowed it to fit inside a General Aircraft Hamilcar glider. The M2 Machine Gun or Browning .50 Caliber Machine Gun is a heavy machine gun designed toward the end of World War I by John Browning.  Its design is similar to Browning's earlier M1919 Browning machine gun, which was chambered for the .30-06 cartridge.  The M2 uses the much larger and much more powerful .50 BMG cartridge, which was developed alongside and takes its name from the gun itself (BMG standing for "Browning Machine Gun").  It has been referred to as "Ma Deuce", in reference to its M2 nomenclature.  The design has had many specific designations; the official designation for the current infantry type is Browning Machine Gun, Cal.  .50, M2, HB, Flexible.  It is effective against infantry, unarmored or lightly armored vehicles and boats, light fortifications and low-flying aircraft.  The M2 has been produced longer than any other machine gun. The M1919 Browning is a .30 caliber medium machine gun that was widely used during the 20th century, especially during World War II, the Korean War, and the Vietnam War.  The M1919 saw service as a light infantry, coaxial, mounted, aircraft, and anti-aircraft machine gun by the U.S. and many other countries.  Many M1919s were rechambered for the new 7.62×51mm NATO round and remain in service to this day. The LT vz.  34, formally designated as Lehký Tank vzor 34 ("Light Tank Model 34") was a Czechoslovak-designed light tank used mainly by Slovakia during World War II.  Its suspension was based on that of the Carden-Loyd tankette, of which the Czechs had purchased three, plus a manufacturing license, in 1930.  Dissatisfied with the prototypes of the Tančík vz.  33 tankette, the Czech Army decided that it would be easier to design a light tank from scratch rather than modify a tankette's chassis to carry a fully rotating armored turret.  50 were built, the last of which was delivered during 1936, of which the Germans captured 22 - including the prototype, when they occupied Bohemia-Moravia in March 1939, but they promptly scrapped them.  The Slovaks seized the remaining 27 (18 + 9 nine LT vz.  34 light tanks which the Czechs had evacuated from Carpatho-Ukraine to Humene and Prešov.)  when they declared independence from Czechoslovakia at the same time.  In Slovak service it only saw combat during the Slovak National Uprising. The M2 light tank, officially Light Tank, M2, was an American pre-World War II light tank which saw limited use during World War II.  The most common model, the M2A4, was equipped with one 37 mm M5 gun and five .30 cal M1919 Browning machine guns.
Answer: M1919 Browning