The right answer is The zygote has 56 chromosomes, 28 inherited from the mother and 28 from the father.
In diploid organisms such as mammals, each individual has two copies of each gene, one from the mother and the other from the father (exception: sex chromosome genes). If these two versions are identical, the individual is said to be homozygous for the gene considered. In the opposite case, it has two different versions (two different alleles), and it is heterozygous for this gene.