A science teacher wants to promote scientific thinking by involving students…

Inquiry-based learning is a student-centred pedagogical approach in which learners actively generate their own hypotheses and design experiments or investigations to test those ideas, rather than receiving conclusions passively from the teacher. It is grounded in constructivist theory, which holds that scientific understanding is built through direct engagement with the process of enquiry -- questioning, predicting, testing, and revising -- rather than through transmission of ready-made facts.

The scenario describes exactly this process: students are asked to form hypotheses and then plan experiments to test their ideas. This is the defining behavioural signature of inquiry-based learning, so the teaching approach that best represents the nature of science education here is the one built around student-formed hypotheses and student-planned experiments.

• Structured demonstration with explanation by the teacher: the teacher performs the procedure and explains each step; students mainly observe rather than generate or test their own hypotheses.

• Inquiry-based experiments with student input: students formulate their own hypotheses and plan their own experiments, matching the described activity directly.

• Memorization of factual content: students commit established facts to memory without forming or testing any hypothesis of their own.

• Shared reading of textbook passages: students absorb conclusions already reached in the text, with no hypothesis generation or experimental design involved.

Only one of the four approaches requires students to originate their own hypotheses and design their own tests, which is exactly what the scenario describes.