Which of the following statements is correct?

(1)They are very sensitive to air pollution and are often used as bioindicators to assess air quality. The presence or absence of certain lichen species can provide valuable information about the pollution levels in a given area.
(2) The algal component in lichens is known as phycobiont.
(3) The fungal component in the lichens is known as mycobiont.
(4)Lichens are known to be excellent pollution indicators. They are not commonly found in areas with high pollution levels.