Angiosperms can use Insects animals and wind but not water.
so your answer is water.
Double fertilization results in the formation of one diploid embryo and a triploid endosperm. Double fertilization is characterized by the formation of two embryos; the embryo proper which is diploid and the fusion product of the central cell with one male gamete which is triploid. This secondary triploid zygote develops into the endosperm.
A possible reason for the transition of algae from unicellularity
to multicellularity would be the evolution of multicellularity allowed algae to
develop traits that keep them close to the land and thus a source of nutrients.
The correct answer between all the choices given is the last choice. I
am hoping that this answer has satisfied your query and it will be able to help
you in your endeavor, and if you would like, feel free to ask another question.