The correct option is C Sphagnum
Sphagnum is one of the most important plant genera in the world. Sphagnum is one of the few bryophyte genera able to dominate an ecosystem. A healing ointment prepared by Sphagnum leaves mixed with grease is used in the treatment of cuts and wounds. The decoction prepared by boiling dried Sphagnum in water, is used in the treatment of acute haemorrhage. This decoction is used to cure diseases of eyes. The lakes where sphagnum grows are called as Sphagnum bogs. These are well known to produce peat in acidic water. The bog water is antiseptic and has astringent properties. Sphagnum exhibit strong antibacterial properties against Gaffkeya tetragena and Staphylococcus aureus. Sphagnum peat is suitable for production of low and intermediate BTU gas as well as hydrogen , ethylene , natural gas , methanol and gasoline. Sphagnum is used as an effective filtering and absorption agent for the treatment of waste water and effluent of factories with acid and toxic discharge consisting of heavy metals particularly Ag, Pb, Cu , Hg, Fe , Sb and organic substances like detergents, dyes, microorganisms and soils.