context: Douglas's business grew astronomically with the onset of World War II, employing as many as 44,000 people in 1943. To defend against air attack set designers from the Warner Brothers Studios prepared elaborate camouflage that disguised the factory and airfield. The RAND Corporation began as a project of the Douglas Company in 1945, and spun off into an independent think tank on May 14, 1948. RAND eventually acquired a 15-acre (61,000 m²) campus centrally located between the Civic Center and the pier entrance.
question: డగ్లస్ వ్యాపార వృద్ధికి కారణమేమిటి?
answers: World War II