Answer:
The options are
A.Independent assortment
B. Mutation
C. Crossing over
D. Non disjunction
The answer is A.Independent assortment
Step-by-step explanation:
Independent assortment of genes involves the separation of genes during the formation and development of reproductive cells.
A boy has XY chromosome and a lady has XX chromosomes. This explains why Sue inherited the mother's copy of chromosome 13 but their father's copy of chromosome 14 while her brother Billy inherited their father's copy of both chromosomes 13 and 14. He inherited both due to the presence of XY chromosomes.