Endosperm of angiosperms results after fertilization from

By double fertilization is formed

What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.

The nuclei of the sperm and egg fuse as a result of

Triple fusion in angiosperms is the fusion of second male gamete with

Syngamy and triple fusion is called ... $A$... The central cell becomes ...$B$... develops into ...$C$... and zygote develops into ...$D$...

$A, B, C, D$ in the above statement are