Question: The CASA 2. 111 was a medium bomber derived from what German aircraft that was designed by Siegfried and Walter Gunter at Heinkel Flugzeugwerke in 1934?
Context: Heinkel Flugzeugwerke (] ) was a German aircraft manufacturing company founded by and named after Ernst Heinkel.  It is noted for producing bomber aircraft for the Luftwaffe in World War II and for important contributions to high-speed flight, with the pioneering examples of a successful liquid-fueled rocket and a turbojet-powered aircraft in aviation history, with both Heinkel designs' first flights occurring shortly before the outbreak of World War II in Europe. The Albatros L 77v was a German tandem two-seat reconnaissance fighter biplane, four examples of which were built under license for Albatros Flugzeugwerke by Ernst Heinkel Flugzeugwerke in 1928.  Based upon the L 76 Aeolus reconnaissance trainer, the aircraft was powered by a 450 kW (600 hp) BMW VI 5.5 water-cooled V12 engine. The Albatros L 76 Aeolus was a military reconnaissance aircraft built by Albatros Flugzeugwerke in 1927.  The plane had wooden dual-spar wings with plywood skins supported by N-type struts and a fabric-covered fuselage made of welded steel tubing.  The aircraft was used for testing, as well as the training of the Soviet Air Force.  It was difficult to fly, and killed many people, including Emil Thuy, who crashed near Smolensk on June 11, 1930, and Paul Jeschonnek, who crashed near Berlin on June 13, 1929.  As a result, it had to be improved, leading to the production of the Albatros L 77v, designed by Ernst Heinkel Flugzeugwerke. Dr. Ernst Heinkel (January 24, 1888 – January 30, 1958) was a German aircraft designer, manufacturer, Wehrwirtschaftsführer in the Third Reich, and member of the Nazi party.  His company Heinkel Flugzeugwerke produced the Heinkel He 178, the world's first turbojet aircraft and jet plane, and the Heinkel He 176, the first rocket aircraft.  He was awarded the German National Prize for Art and Science in 1938. The Heinkel HD 23 was a carrier-borne fighter biplane designed in Germany at Heinkel Flugzeugwerke in the 1920s, for export to Japan.  Two examples were delivered to Aichi as pattern aircraft in 1927.  Aichi added rudimentary flotation capability and built two further examples as the Type H Carrier Fighter, but full-scale production was not started. Hansa und Brandenburgische Flugzeugwerke (more usually just Hansa-Brandenburg) was a German aircraft manufacturing company that operated during World War I.  It was created in May 1914 by the purchase of "Brandenburgische Flugzeugwerke" by Camillo Castiglioni, who relocated the factory from Liebau to Brandenburg an der Havel.  Brandenburg's chief designer, Ernst Heinkel was retained by the new enterprise.  By Autumn 1915, it had become the largest aircraft manufacturer in Germany, with a capital of 1,500,000 Marks, 1,000 employees, and two more factories - one in Rummelsburg, Berlin, and one in Wandsbek, Hamburg. The Heinkel He 343 was a four-engine jet bomber project by Ernst Heinkel Flugzeugwerke in the last years of the Third Reich. The Jumo 211 was an inverted V-12 aircraft engine, Junkers Motoren's primary aircraft engine of World War II.  It was the direct competitor to the famous Daimler-Benz DB 601 and closely paralleled its development.  While the Daimler-Benz engine was mostly used in single-engined and twin-engined fighters, the Jumo engine was primarily used in bombers such as Junkers' own Ju 87 and Ju 88, and Heinkel's H-series examples of the Heinkel He 111 medium bomber.  It was the most-produced German aero engine of the war, with almost 70,000 examples completed. The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter at Heinkel Flugzeugwerke in 1934.  Through development it was described as a "wolf in sheep's clothing" because the project masqueraded the machine as civilian transport, though from conception the Heinkel was intended to provide the nascent Luftwaffe with a fast medium bomber. The CASA 2.111 was a medium bomber derived from the Heinkel He 111 and produced in Spain under licence by Construcciones Aeronáuticas SA (CASA).  The 2.111 models differed significantly in details from Heinkel's wartime He 111H design while using essentially the same exact airframe in appearance, featuring heavier armament and eventually Rolls-Royce Merlin engines.
Answer: The Heinkel He 111