Mutations of Regulatory Elements of Developmental Genes May Have Either

Mutations of regulatory elements of developmental genes may have either dominant or recessive effects. If a mutation results in a silencer element that negatively regulates, which do you expect?

A) a recessive effect in which cis elements are up-regulated
B) a recessive effect in which cis elements are down-regulated
C) a dominant effect in which the silencer down-regulates gene activity
D) a dominant effect in which gene activity is up-regulated
E) a dominant effect in which the silencer is trans-activating