Final answer:
The stage where young people develop the capacity for abstract and scientific thinking is the Formal operational stage (C), starting from around age 11 onwards. This stage allows for the understanding of abstract concepts, scientific reasoning, and the ability to consider hypothetical situations.
Step-by-step explanation:
The developmental stage in which young people develop the capacity for abstract, systematic, scientific thinking is C. Formal operational stage. This stage is the final stage in Jean Piaget's theory of cognitive development, beginning from around age 11 into adulthood. At this stage, unlike the concrete operational stage, adolescents can think abstractly, deal with hypothetical situations, and engage in sophisticated problem-solving. It encompasses the ability to understand abstract concepts, undertake scientific reasoning, and entertain possibilities beyond the immediate environment.
Different from earlier stages like the preoperational stage and the concrete operational stage, the formal operational stage allows for the use of abstract thinking to solve problems, look at alternative solutions, and test hypotheses. This stage marks a significant shift in cognitive abilities, allowing for more complex thought processes and hypothetical reasoning. The development of these abstract thinking skills is vital for scientific reasoning and logical problem solving that will be used throughout adulthood.