Inquiry-based curriculum is based on—

Inquiry-based curriculum is grounded in heuristic reasoning—a problem-solving approach where learners discover knowledge through exploration, investigation, and self-directed inquiry. The heuristic method (developed by H.E. Armstrong) emphasizes 'learning by doing' and self-discovery, which is the core of inquiry-based learning. Students ask questions, investigate, and arrive at conclusions through their own efforts. Hence (3) heuristic reasoning is correct.