An Island Is on the Migration Route of Sea Birds

An island is on the migration route of sea birds. What best describes the way this will change Hardy-Weinberg equilibrium in non-migrating populations, if the migrating birds have very different allelic frequencies?

A) Mutations will shift the allele frequency of the island sea birds and alter their phenotype.
B) Equilibrium will be changed due to the genetic nonrandom mating occurring introducing new alleles.
C) Equilibrium may be altered nearer to a 0.5 frequency and therefore alter the allelic structure of the island birds.
D) Natural selection will become stronger in the tree nesting birds.
E) The 0.5 equilibrium will be greatly altered due to influencing frequencies from migrating birds.