In angiosperms, triple fusion is required for formation of

Angiosperms have a unique phenomenon of double fertilisation in which after the release of two male gametes inside the embryo sac by the pollen tube, one male gamete (first male gamete which is closest to the egg) fuses with egg nucleus and this phenomenon is known as fertilisation or syngamy and results in the formation of zygote.

The other male gamete i.e. the second male gamete migrates towards the secondary nucleus (formed from fusion of two polar nuclei) and fuses with it. This phenomenon is known as triple fusion and results in the formation of a triploid primary endosperm mother cell. Primary endosperm mother cell then undergoes further divisions to form endosperm. Hence, triple fusion is required for the formation of endosperm.

So, the correct answer is B.