Descendants of a Small Rodent-Type Animal Have Been Identified in North

Descendants of a small rodent-type animal have been identified in North Asia and Europe. The relationship has been confirmed by DNA analysis which also demonstrated that the two species diverged around 20 million years ago. This suggests that

A) a continuous population has been separated by environmental fragmentation, producing two separate populations that evolved into separate species.
B) the two populations were separated by plate tectonics.
C) a common ancestor existed on Gondwana.
D) Eurasia separated after 20 million years ago.
E) Pangea separated before 20 million years ago.