The right answer is B (in the most of the cases).
The crossing-over (equilibrium) corresponds to an intercrossing of homologous chromosomes that, during meiosis I, exchange certain chromatid fragments after pairing, leading to a mixture of the genes they carry.
Cross-over occurs only in heterozygous individuals (with linked genes, that is, two genes on the same pair of homologous chromosomes). The heterozygous individual, after crossing-over, will produce parental gametes and recombinant gametes.
In homozygous individuals, the crossing-over has no influence on the combination of the alleles, since they are identical.
