The correct option is
D All of the above
D. All of the above
Reason: Siphonogamy is a condition in plants in which pollen tubes are developed for the transfer of the male cells to the eggs. It generally occurs in spermatophytes or seed producing plants. Spermatophyte can be divided in two classes, gymnosperm and angiosperm. Angiosperms can be divided into classes again. Those are monocot and dicot. So option D is correct.