Most First Time Migrant Birds Reach Their Destination Without Knowing

Most first time migrant birds reach their destination without knowing where that goal is located. To do this they may make use of an innate process called vector navigation. Evidence supporting the idea of vector navigation is the finding that

A) cross-bred members of two populations that had very different migratory directions produced offspring that failed to reflect the migratory direction of either parent population.
B) individual birds held in the laboratory continue to flutter in their characteristic migratory direction even after their counterparts in the wild have completed their migratory journey.
C) individual birds held in the laboratory flutter in the direction in which they would be flying if they were free.
D) individual birds held in the laboratory maintain their original course of direction, even when free-flying members of their population have changed direction.