The correct option is D All of the above
Formation of endosperm which is triploid in nature in angiosperms will be found in monocarpellary, bicarpellary and polycarpellary condition.
Monocarpellary - only one single carpel present.
Bicarpellary - two carpels present
Polycarpellary - more than two carpels which include tetra carpellary, pentacarpellary and so on.