Study the given flow chart. Which of the following are the correct examples of W, X, Y and Z?

• A. W- Ulothrix, X-Marsilea, Y-Selaginella, Z-Cycas
• B. W-Riccia, X-Marsilea, Y-Cycas, Z-Ipomoea
• C.  Earth's magnetic field
• D. W-Spirogyra, X-Dryopteris, Y-Funaria, Z-Pinus