The correct options are
B sequence of genes
D gene position
In a cell, the chromosomes are in two sets: one of which is derived from the mother and the other from the father. The chromosomes that have the similar sequence of genes or homologous chromosomes are paired during meiosis.
A human cell contains 23 pairs of homologous chromosomes: 22 of them are homologous non-sex chromosomes (or autosomes) and 1 pair of sex chromosomes. In females, the homologous sex chromosomes are 2 Xs; in males the sex chromosomes are heterologous and they are X and Y chromosomes.