What are the names of the chemoreceptors that respond to molecules in air and water

The correct answer is peripheral chemoreceptors.

Explanation:

The peripheral chemoreceptors are named so as they are considered as the sensory extensions of the PNS into the blood vessels where they determine variations in the chemical quantities. These polymodal sensors react towards the changes in the number of blood properties, comprising the peripheral chemoreceptors in air versus water breathers.  

The peripheral chemoreceptors comprise carotid and aortic bodies. The aortic body determines variations in the carbon dioxide and oxygen present in the blood, however, not the pH, while the carotid body determines all the three.  

Option D, Echinoderm

Explanation:

Deuterostome are species which are bilalteral in structure and the first embryonic opening becomes the anus.  

There are three classes of deuterostome namely  

•Chordata  

•Echinodermata  

•Hemichordata  

The sea urchin belongs to the phylum Echinodermata which have radial symmetry (includes starfish etc.) and have a unique a water-vascular system (hydraulic system) which is used for respiration, locomotion and transportation of food item.  

Thus, option D is the correct answer.