Which animal has unpaired lungs?

In insects,respiratory gas exchange occurs through

$O_{2}$ exchange with $CO_{2}$ by simple diffusion over the entire body surface takes place in:
$I.$ Sponges
$II.$ Coelenterates
$III.$ Flatworms
Select the correct option to complete the given statement.

Choose the correct option by matching the organisms in Column-$I$ with their respective respiratory organs in Column-$II$.

Column-$I$	Column-$II$
$(p)$ Sponges	$(I)$ Through tracheal tubes
$(q)$ Insects	$(II)$ Through lungs
$(r)$ Molluscs	$(III)$ Vascularized gills
$(s)$ Reptiles	$(IV)$ Simple diffusion over their entire body surface
	$(V)$ By their moist cuticle

Find the correct sequence for $p-q-r-s$.

In which of the following animals,respiration occurs without any respiratory organ?

The respiratory pigment that contains $Cu$ is -