Put your knowledge of shooting in Aperture Priority and how apertures will affect depth of field in a photo to work.
Create a creative photo that uses depth of field with a purpose. Maybe it's a portraitwith a small d.o.f. to bring the focus onto your subject. Maybe it's a landscape with a large d.o.f. tohighlight all of the details of the scene.
The subject and d.o.f. is up to you, but your photo must: -have strength and clarity -be in focus somewhere in the photo (even if the focused area is small) -be in focus on the main subject to be highlighted -use elements of composition -be edited in some way (clone out dust spots, add contrast, crop, etc.)