Lichens are able to obtain nutrients from their environment by:

a. digesting small organisms that live on the surface of the lichen

b. combining photobionts with chyrtid mycobionts

c. secreting substances that release nutrients from surrounding materials

d. forming close connections with plant roots

b is the answer and if you need further with anything message me

here is the answer

water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. weathering is the breaking down or dissolving of rocks and minerals on earths surface. once a rock has been broken down, a process called erosion transports the bits of rock and minerals away.