A plant has leaves that contain both green regions and white regions. On one leaf, part of the surface is covered with aluminium foil so that light cannot reach it. The plant is then kept beneath a lamp for 24 hours. After this period, discs are removed from the leaf areas shown and examined using iodine solution. Which leaf discs will turn blue-black when iodine solution is added?
- AW and X
- BX only
- CY and Z
- DY only