What is genetic equilibrium?

(1) When all the alleles of a gene are present in a population in equal frequencies

(2) When the number of heterozygotes in a population are equal to the number of either of the homozygote

(3) When the number of heterozygotes in a population are equal to the number of either of the homozygote

(4) When the frequency of particular genes or alleles remain constant in a population through generations