If more than two sets of chromosomes are present then that condition is called polyploidy. The correct answer should be B because diploid male undergo meiosis and give rise to haploid male gamete(n). Similarly, the tetraploid female gamete undergoes meiosis that also gives rise to gametes (2n). These female gametes ( $2\mathrm{n}+2\mathrm{n}$ polar nuclei) fuse with a male gamete that gives rise to pentaploid endosperm.