What Makes It Possible for the Coexistence of Several Warbler

What makes it possible for the coexistence of several warbler species that feed on the same insect larvae?

A) The birds eat in the same area of different fir and spruce trees.
B) The birds eat in the different portions of the forest canopy.
C) The birds eat in the same portion of different evergreens.
D) The warblers do not experience intraspecies competition.
E) Some of the warblers are diurnal and some nocturnal.