The correct option is B Cuscuta
Symbiotic relationships are achieved when both the participants are benefited from the relationship. Fungi and algae are in a symbiotic relationship called lichen.
In lichen, fungi provide shelter and water to algae and the algae provides food to the fungi.
Rhizobium is in a symbiotic relationship with leguminous plants where Rhizobium fixes nitrogen for the plant and gets food and shelter in return. But, Cuscuta is a parasite and in parasitism, the organism benefits at the expense of another organism.