Final answer:
The core belief is that distinctions and concepts are subjective and cannot be universally objective or directly based in reality, which aligns with Kant's transcendental idealism. The closest match in the provided options to Kant's view is that concepts exist separately from the physical world and do not have tangible connection to reality.
Therefore, option C is correct.
Step-by-step explanation:
The core belief about distinctions and concepts being discussed is that all distinctions and concepts are intertwined with our subjective experience and therefore are not considered universally objective or directly based in reality. According to the references, Kant postulates that rules for thoughts, which he calls 'categories,' are innate and necessary for understanding concepts such as causation, substance, self, identity, space, and time. These categories are fundamental to organizing our empirical concepts and judgments. While concepts cannot be directly experienced, they are involved in judgments of objects within our spatio-temporal experience. Thus, knowledge is limited to empirical observation, and the true nature of objects as they are in themselves is unknowable to us, aligning with Kant's transcendental idealism.
Based on the information provided, none of the options from the multiple-choice question accurately reflect the core belief. However, if forced to select the most applicable, option (c) 'Concepts exist separately from the physical world and do not have any tangible connection to reality' seems to be the closest match to Kant's beliefs, as it encapsulates the transcendental aspect of Kant's ideas without asserting that concepts have no basis in reality.