They are composed of proteins. I cannot see the options but hopefully that answer is in one of them
Since most fungi and decomposers are Saptotrops, The answer is most likely A; Saprobic.
Viruses are made of one or more nuclei acid molecules surrounded by a coat protein or capsid. So the core of the virus will contain the viral genome. Some viruses' capsid maybe enclosed with an envelope derived from the host cell (the cell that the virus is infecting), and this envelope is also derived from the host cell membrane.
