A team of researchers decide to study social mobility. They obtain data on respondents and their parents, gathering information on the occupational status of each generation to see if mobility has occurred. To understand the likelihood of social mobility more fully, they also ask questions about respondents' educational attainment, type of training, and the prestige of the first job that respondents had in their respective occupational field. By considering some of these intervening processes, this research team has chosen to use a(n) approach to social mobility. a. status attainment model b. ascending mobility c. vertical mobility d. class-based