The condition( s ) that allow( s ) a population to exist in genetic equilibrium is/are:

• A

  Mutations leading to an increase in fitness should occur.
• Correct answer
  B

  Migration of individuals should be prevented so that alleles found in one area may not get removed from or introduced into other areas.
• Correct answer
  C

  All individuals in a population should have an equal chance of survival.
• Correct answer
  D

  Random changes in allelic combinations occurring during meiosis should get absorbed without any scope for their preferential multiplication.

Hence, the correct answer is options: 'B', 'C', 'D'.