When we are talking about genetics dominance is a phenomenon of one allele of a gene on a chromosome that masks the effect of a different variant of the same gene on the other copy of the chromosome. Genes don't have parties and sweaters so A is not an option here. They also can't surrender and even if they did they couldn't discuss anything. And they most certainly don't obliterate each other.
The diploid number is restored when the two haploid cells combine to create a zygote. Basically when the sperm cell enters the egg cell and makes the offspring.
