Jim, a researcher, attempts to test the effect of the environment in an examination hall on a student's performance. However, he gives students question papers that differ in complexity and subject matter. His results would not be reliable because the complexity and subject matter of the examination are.

In the kingdom of saudi arabia the government controls every aspect of oil production which makes up the majority of the country's economy. while other businesses are owned by individuals, the biggest segment of saudi arabia's economy is oil production. saudi arabia's economy would best be described as a) entirely market. b) almost entirely command. c) a mixture between just market and traditional. d) a mixed economy with large amounts of command.