Concept:A mature toad exchanges gases through its skin, lungs, and the lining of its mouth.
Explanation:Gills are present only in the tadpole stage, not in the adult toad.
The eardrum is meant for hearing and does not take part in gaseous exchange.
Option A includes gills and eardrum, so it is wrong.
Option B includes eardrum, so it is wrong.
Option C mentions gills, which are not present in a mature toad.
Therefore, the correct organs are skin, lungs, and mouth.
Answer:D. Skin, lungs and mouth