Concept:An open-ended question has no single correct answer. It requires thinking and exploration beyond textbook facts.
Explanation:Option D asks: “What would happen if period of rotation and revolution of moon are different?” There is no fixed answer in the textbook. Students must apply concepts of rotation, revolution, and their effects to imagine possibilities.
Options A, B, and C each have a definite, textbook-based answer. For example, “Why do we see only one face of moon?” has a specific scientific explanation. Such questions do not encourage divergent thinking.
Therefore, only option D is open-ended as it promotes creativity and deeper understanding.
Answer:D. What would happen if period of rotation and revolution of moon are different?