The Different Strains of Phlox Drummondii Growing in European Nurseries

The different strains of Phlox drummondii growing in European nurseries illustrate that

A) in some cases,reproductive isolation requires millions of years.
B) speciation can occur without geographic isolation.
C) speciation can occur rapidly through allopolyploidy.
D) partial reproductive isolation has been documented in human history.
E) chromosomal rearrangements can result in reproductive isolation via the Dobzhansky-Muller model.