Which would have the highest surface area to volume ratio? A slug, an earthworm or a tapeworm?

A tapeworm has the highest surface area to volume ratio. A tapeworm being flat has little volume but a lot of surface area. Take a piece of paper vs a pencil for example; a pencil is round and has many sides but also contains much volume in the middle whereas a piece of paper has almost no volume and two sides with tons of surface area.