Study the given flow chart and identify the objects W, X, Y and Z.
| W | X | Y | Z | |
|---|---|---|---|---|
| A | Clay tile | Steel sheet | Aluminium foil | Chalk |
| B | Rubber band | Glass | Iron rod | Clay tile |
| C | Sponge | Steel sheet | Clay tile | Glass |
| D | Iron rod | Rubber band | Chalk | Glass |
Option D is correct