The correct option is B triple fusion
Eucalyptus is an angiosperm whereas Cedrus is a gymnosperm. Both show syngamy of their gametes but the seeds formed in gymnosperms are naked while those in angiosperms are covered by a fruit. In addition to syngamy, angiosperms also undergo triple fusion i.e a male gamete fuses with the diploid secondary nucleus in the embyro sac to produce a triploid primary endosperm nucleus (PEN). Triple fusion is absent in gymnosperms.
Archegonia is the female reproductive organ in bryophytes.