The Philadelphia chromosome is

A、an example of an aneuploidy;

B、the result of a translocated chromosome involving parts of chromosomes 9 and 22.;

C、a lengthened version of chromosome 22 that results from a recombination event with chromosome 12.;

D、a shortened version of chromosome 22 that results from a deletion.;

E、a lengthened version of chromosome 22 that results from a duplication.