{"knowledge_schema": {"broad_category": "Chemistry \u2192 Stereochemistry \u2192 Optical Activity", "refinement": "This problem involves identifying compounds that possess chiral centers, which are necessary for optical activity.", "specific_scope": "The focus is on analyzing a list of specific organic compounds to determine how many of them are optically active based on their stereochemistry.", "goal": "Count the number of compounds that exhibit optical activity due to the presence of chiral centers."}, "summary": "In this problem, we are tasked with determining how many of the given organic compounds exhibit optical activity, which is a property of chiral molecules. A compound is optically active if it has at least one chiral center and is not superimposable on its mirror image. By analyzing the provided compounds, we find that three of them meet the criteria for optical activity, leading to the conclusion that the answer is 3."}