Concept:Inquiry-based learning is a student-centered approach that focuses on active investigation, questioning, and exploration rather than passive reception of information.Explanation:The central element of an inquiry-based lesson plan is exploratory tasks. In these tasks, students actively investigate problems, ask questions, and discover concepts through hands-on activities, experiments, and guided exploration. This approach builds deeper understanding and critical thinking. While exposition (initial presentation) is necessary, it alone does not define inquiry. Extended learning tasks help reinforce concepts but are typically follow-up activities, not the core. Cross-curricular integration can be included but is not the primary focus of inquiry-based learning. Thus, exploratory tasks best capture the essence of the inquiry process.Answer:B. Exploratory tasks