Information:  - Mercedes-Benz is a global automobile manufacturer and a division of the German company Daimler AG. The brand is known for luxury vehicles, buses, coaches, and trucks. The headquarters of Mercedes-Benz are in Stuttgart, Baden-Württemberg, Germany.  - Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche AG, is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans. Porsche AG is headquartered in Stuttgart, and is owned by Volkswagen AG, which is itself majority-owned by Porsche Automobil Holding SE. Porsche's current lineup includes the 718 Boxster/Cayman, 911, Panamera, Macan and Cayenne.  - Karl Rabe ( 29 October 1895 , Pottendorf , Austria - 28 October 1968 ) was an automobile designer and was the Chief Designer at Porsche . He helped Ferdinand Porsche to develop the Porsche 's transmissions .  - Ferdinand Porsche (3 September 1875  30 January 1951) was an automotive engineer and founder of the Porsche car company. He is best known for creating the first gasoline-electric hybrid vehicle (Lohner-Porsche), the Volkswagen Beetle, the Mercedes-Benz SS/SSK, several other important developments and Porsche automobiles. In addition, Porsche designed the 1923 Benz Tropfenwagen, which was the first racing car with a mid-engine, rear-wheel drive layout.    After reading the paragraphs above, we are interested in knowing the entity with which 'karl rabe' exhibits the relationship of 'occupation'. Find the answer from the choices below.  Choices: - engineer  - manufacturer
The answer to this question is:
engineer