The correct option is C Fungus and algae
Lichens are association (mutually beneficial) between fungus and alga.
The fungal partner is mycobiont and algal partner is phycobion. The
mycobiont is usually an ascomycete and phycobiont is usually green algae
Lichens can grow in extremely inhospitable conditions In many
ecosystems they are the pioneer species. The role of mycobiont is
providing body structure and anchorage and absorption of minerals and
water. The role of phycobiont is mainly in providing food through
photosynthesis. So, the correct answer is 'Fungus and algae'.