Step 1: Learn the four groups.
Aquatic organisms are sorted by where they live and how they move. Periphyton cling to surfaces, epineuston live on top of the water, nekton swim freely, and benthos live on the bottom.
Step 2: Place periphyton.
Periphyton are organisms attached to plants or submerged surfaces. The nymphs of insects fit this group. So A goes with II.
Step 3: Place epineuston.
Epineuston live on the upper surface of the water. Dineutes, the whirligig beetle, moves on the surface. So B goes with III.
Step 4: Place nekton.
Nekton are strong, active swimmers. Dytiscus, the diving beetle, swims actively through the water. So C goes with IV.
Step 5: Place benthos.
Benthos live at the bottom of the water body. Chironomid larvae stay on the bottom mud. So D goes with I.
Step 6: Read the final match.
The match is A-II, B-III, C-IV, D-I, which is the fourth option.
\[ \boxed{\text{A-II, B-III, C-IV, D-I}} \]