In which of the following examples for natural selection, the end result is a two-peak curve?

A two peak curve is observed in disruptive selection which is due to speciation. Thus, evolution of different species of Darwin's finches from the common seed eating ancestor  is a Disruptive  selection.

Melanic moths are dominant compared to dark coloured moths in England after industrialization - Directional selection.

Average weight babies survive better than heavy weight or low weight ones in England - Stabilizing selection.

A population of purple sea urchins stays purple, as starfish eat other colors - Stabilizing selection