Step 1: Analyzing the sequence of events.
The girls entered the room in turns, and each girl observed different shapes on the wall. Samantha saw both the triangle and the circle, while Reema saw only the triangle, and Payal saw only the circle. This implies that the shapes on the wall are changing based on the lighting conditions in the room.
Step 2: Understanding the light conditions.
- When Samantha entered, the room was lit by a white light, revealing both the triangle and the circle.
- When Reema entered, the light changed to red, and only the triangle was visible.
- When Payal entered, the light changed to blue, and only the circle was visible.
Step 3: Conclusion.
The correct answer is (C) because the lighting sequence explains the changes in the shapes observed by the girls.