Answer:b. A sperm nucleus fuses with an egg cell and a sperm nucleus fuses with polar nuclei.
Step-by-step explanation:
This mode of fertlization occurs only in angioseprms .One of the sperms forms 2n as zygote.
The second sperm fuses with the two polar nuclei to form 3n as endosperm.
The importance of these are:
1. Restoration of diploid condition with the fusion of haploid male and female gametes.
2.it makes plants to recieve stimulus based on which ovary develops into a fruit and shows thst it is ovules that develops into seeds.