Rob's grandfather and father were factory workers. When Rob graduated from high school, he took a job at the factory too, but after three years, he was laid off. The company had moved the factory to China. Rob now works as a waiter in a local restaurant. If you are focused on the fact that Rob switched jobs because the economy shifted, you would say this is an example of: a. individual mobility b. the feminization of poverty. c. structural mobility d. vertical mobility