The correct option is B phycobiont, mycobiont
Lichens are symbiotic associations i.e., mutually useful associations, between algae and fungi. The algal component is known as phycobiont and fungal component as mycobiont, which are autotrophic and heterotrophic, respectively. Algae prepare food for fungi and fungi provide shelter and absorb mineral nutrients and water for its partner.
Viroids are the free RNA without a protein coat.