Indicate If Each of the Following Descriptions Matches Lithotrophic (L)

Short Answer

Indicate if each of the following descriptions matches lithotrophic (L), organotrophic (O), or phototrophic (P) organisms. Your answer would be a four-letter string composed of letters L, O, and P only, e.g. LLPP.
( ) They feed on other living organisms or their organic products.
( ) They are responsible for the current oxygen-rich atmosphere of the Earth.
( ) They are all known to be prokaryotic.
( ) They are the primary energy converters in hydrothermal vents in the ocean floor.