The correct option is A Cephaleuros
Cephaleuros, genus of thalloid algae with 14 species is a parasitic algae, that infect plants and causing red rust. This grows as a parasite on important economic plants and trees such as tea, mango, coffee and guava. Harveyella is a colorless red algae, which lacks photosynthetic pigments and hence live as parasites on other photosynthetic red algae.