The triple fusion in plants was discovered by

The correct option is D Nawaschin
Triple fusion is also called as double fertilisation was discovered by Nawaschin. It is a common characteristic found in angiosperms. In this case, the two male gametes entering the embryo sac, one will fuse with the egg cell to form the embryo and the other will fuse with secondary nuclei to form endosperm. This gives further nourishment to the growing embryo.

So, the correct answer is option D.