Answer:
The correct answer would be A. Each parent only passes on one-half of its hereditary factors to the offspring.
It can be correctly explained with the help of the law of segregation.
It states that the alleles of each gene get segregated from each other and each gamete produced by a parent would contain only one out of two alleles of a gene.
For example, if the genotype of a parent is Tt, then the gamete would contain either T or t.
Thus, each parent only contributes half of its heredity factors in the form of gametes.