Choose the bioindicator from the list; the growth of this bioindicator is restricted by the airborne pollutant sulphur dioxide.

Bioindicators (biological indicators) are living organisms such as plants, plankton, animals, fungi and microbes that are used to monitor the health of the natural ecosystem. They are used to evaluate environmental health and biogeographic changes in the environment. For example, lichens will perish if sulphur dioxide is present in the region of their habitat. The industrial revolution caused the extinction of numerous lichen species. Due to this characteristic, lichens are regarded as air pollution indicators (bioindicators).