Which statement correctly describes the function of each lichen part? a. algae provide structure, bacteria provide food, and fungi provide nitrogen. b. algae provide nitrogen, bacteria provide food, and fungi provide structure. c. algae provide food, bacteria provide nitrogen, and fungi provide structure. d. algae provide food, bacteria provide structure, and fungi provide nitrogen.

Option C, Algae provide food, bacteria provide nitrogen, and fungi provide structure

Explanation:

A lichen is an association of  algae, fungi and bacteria in such a way that they dwell together thereby forming a symbiotic association where all the co-living species benefit from each other.  

Fungi provide the structure as they form the thallus of the lichen and provide space for  both the bacteria and algae to live along with fungi  

Fungi are heterotrophs and hence they can not prepare food of their own. They depend on autotrophic organisms like algae (which posses chlorophyll) which are able to produce food of their own. Bacteria (Cyanobacteria) provide additional nutrient in the form of nitrogen for better nourishment of  all the organisms in the association

Hence the option C is correct.