Ramu collected 4 small paper cups, two strips of car board with dimensions 20 cm length and 2 cm breadth, gum, stapler, sketch pen and sharpened pencil. Using these materials, Ramu made the apparatus as shown here.
![](https://www.sarthaks.com/?qa=blob&qa_blobid=6507903517078670041)
A) Windmill
B) Thermoscope
C) Anemometer
D) Barometer