A Metapopulation of Wood Thrushes Is Found in an Area

Multiple Choice

A metapopulation of wood thrushes is found in an area of the Midwest.Individual thrush populations exist in forest patches interspersed with farm fields.Monitoring over several years showed several types of populations: I.Populations with negative birth rates that went extinct
II) New populations that occasionally formed in previously bare patches
III) Populations with positive birth rates that maintained population equilibrium
Which of these types would be considered source populations, and which would be considered sink populations?

A) All three types would be sink populations.
B) All three types would be source populations.
C) I and II are likely sink populations; III might be a source population.
D) I and II are likely source populations; III might be a sink population.
E) II and III are definitely source populations; I is definitely a sink population.