Answer:
(D). All of the above.
Step-by-step explanation:
Lichens represent symbiotic association between algae (that provide food for fungi) and fungi (that provide protection and shelter to the algae).
Some lichens can be used to make poisons due to their high toxic content. For example, Letharia (wolf lichen) is used to kill wolves.
Some Lichens are used to produce natural dye. For example, cudbear lichen is used to make red dye.
Some lichens, such as Iceland moos and reindeer lichens can be also used as a food source in various regions.
Thus, the correct answer is option (D).