Imagine that the species differences in song between the medium ground finch and the cactus finch ...

Imagine that the species differences in song between the medium ground finch and the cactus finch were based entirely on genetic differences and could not be influenced by experience.
 
  Do you think the two species would experience more or less gene flow than they currently do?
  a. more gene flow as the hybrid offspring is fully viable and fertile
  b. more gene flow as cultural barriers are always more effective than genetic barriers
  c. less gene flow as F1 males will likely have intermediate songs that are unattractive to either parent species
  d. no difference as genetic differences are just as effective as the cultural transmission of song patterns