Which of the Following Is Not One of the Properties

Which of the following is not one of the properties of gene linkage that Morgan obtained from his experiments?

A) Genes that are on the same chromosome may be inherited together.
B) Crossing over exchanges pieces of chromosomes and creates new allele combinations.
C) The likelihood of crossing over occurring between two genes is dependent on the distance of the genes from one another.
D) Genes that are on the same chromosome are always transmitted together as a unit.