Early in the chapter Santrock suggests that there is an uncertain temporary, or unsettled character to early adulthood. Santrock then discusses various ways adolescents experiment with life before they settle into the decision-making clarity of adulthood. Later in the chapter. Santrock describes several theories of adult cognitive development that might be applied to understanding young adults' uncertainties from another point of view. Of the following stages or characteristics taken from the various theories, which best explains adolescents' delay in making decisions? a formal operations (Piaget) b. pragmatic constraints view (Labouvie-Vief) c. relativistic thinking (Perry) d postformal operations (Piaget)