A type of lichen grows on rocks at the base of a waterfall. Which factor in the lichen's environment is abiotic?

The answer is D. Moisture level around the waterfall

An abiotic factor is n ot associated with living organisms. Environmental a biotic factors include sunlight, temperature, wind and rainfall. For any plant living at the base of a waterfall, we can expect a very moist environment for a high proportion of the time. Therefore, the abiotic factor in this case is high moisture.