How Is the Prairie Vole an Example of a Biparental

How is the prairie vole an example of a biparental species?

A) Prairie voles often mate in multiple pairings throughout their life.
B) They have the ability to develop into males or females depending on their environment.
C) They only bond for the first week, and then the male finds a new partner to bond.
D) Both vole parents participate in building a nest, hoarding food, and tending to the pups.