Recessive alleles at Hardy-Weinberg equilibrium
Let's go through the possible answers. Which of the following could be predicted? Not (1), because we don't know whether selection favors or disfavors the recessive alleles. Not (2) for the same reason. Not (4) by definition. Not (5) because recessive alleles don't magically become dominant. 

This leaves us with (3), which also seems correct: not only do we know that frequencies don't change under the Hardy-Weinberg assumptions, but also an equilibrium is by definition a state at which frequencies remain the same. 

An aside: this question fairly clearly recalls G. Udny Yule's confusion about the fate of recessive alleles, which lead Punnett to enlist G. H. Hardy's help in deriving Hardy-Weinberg equilibrium. Yule expected recessive alleles to decline in frequency by virtue of their recessiveness; Hardy showed otherwise.